なぜ?どうして?科学のお話 - Section 3 Discussion Thread

Section 3 - 生き物の話 2 Reading Thread

Start date: Apr 6
Pages: 86-114
(new edition)
(Pages 78-106 in the old edition)

Main なぜ?どうして?科学のお話 thread: Link
Last section: Section 2
Next Section: Section 4


Daily Schedule

Daily reading schedule (new edition)

(Subtract 8 to get the corresponding page number in the old edition)

Date Page Chapter
Apr 6 86 Fireflies
Apr 7 87
Apr 8 88
Apr 9 89
Apr 10 90 Doodlebugs
Apr 11 91
Apr 12 92
Apr 13 93 Insect Breathing
Apr 14 94
Apr 15 95
Apr 16 96 Insect Catching Plants
Apr 17 97
Apr 18 98
Apr 19 99
Apr 20 100
Apr 21 101 Chloroplasts
Apr 22 102
Apr 23 103
Apr 24 104 Pollen
Apr 25 105
Apr 26 106
Apr 27 107 Flower Breathing
Apr 28 108
Apr 29 109
Apr 30 110 Experiments
May 1 111
May 2 112
May 3 113
May 4 114

For ebook readers

Last lines of each page

Kindly provided by @Sansarret:
86 - 光っているのは おしりに 近い ところです。
87 - 合図を おくったりしていると いわれています。
88 - オスは、メスの 光を 見つけると、強い 光を
89 - ホタルに なってからです。 (end of chapter)
90 - アリが おちてしまっと 出られません。アリに
91 - くると、すばやく とびかかって、
92 - ところなのですね。 (end of chapter)
93 - こん虫は、この 気門を、ひらいたり、とじたりして、
94 - からだの すみずみへと、空気が おくられます。
95 - 出して いきを します。 (end of chapter)
96 - 虫を つかまえて 食べる 植物の ことを、
97 - 生きるための えいように しているのです。
98 - くっつけてしまいます。
99 - 入ると、いっしゅんで
100 - かんさつしてみましょう。 (end of chapter)
101 - 植物は、生きるための えいようを おもに
102 - あるからなのです。
103 - 光を たくさん とりこもうと しているのです。 (end of chapter)
104 - のこすと いう ことです。
105 - じゆうに うごきまわる ことが できません。
106 - めしべに 届けます。 (end of chapter)
107 - 葉っぱに ある あなから 「さんそ」を とり入れて,
108 - こきゅうとは はんたいに、
109 - 生きていけるのです。 (end of chapter)
110 - 下の 方、ジャガトモの かわなどです。
111 - あつめに 切ってもらいましょう。
112 - えいようが たくさん
113 - えいようが たくわえられています。
114 - 一部なのですね。 (end of section)

Discussion guidelines

  • Please make sure to mark the page number on top of your post. For the sake of clarity, let’s follow the numbering in the new edition. (If you have the old edition, subtract 8 to get the corresponding page number in the old edition.)
  • Don’t be afraid of asking questions, even if they seem embarrassing at first. All of us are here to learn and someone else will probably be grateful you asked!
  • To you lurkers out there: join the conversation, it’s fun!

Vocabulary sheet

Kindly created by @frayderike.


  • I am reading along :grin: :sparkler: :congratulations:
  • I am still reading but I haven’t reached this part yet :man_technologist:
  • I have stopped reading this book :balloon:

0 voters


p. 86

Why do the fireflies‘ butts shine?


Have you ever seen, in early summer nights, shining fireflies flying near rivers or paddy fields?


Isn’t it wonderful how the faint lights switch on an off?


The shining spot is near the butt.


Page 86.

ホタルは なぜ おしりが 光るの?

How does the butt of the firefly glow?

夏の 初めの 夜、川や 田んぼの そばで、 ホタルが 光ながら とんでいるのを 見た ことが ありますか。

Can you see the firefly light up while flying near the river and rice fields in the beginning of a summer night?

ほのかな 光が、 ついたり きえたりして、 とても ふしぎですね 。

The faint light that lights off and on is really amazing isnt it?

光っているのは おしりに 近い ところです。

The shining is in a place near the butt.


We have again a little difference with 夏の始めの夜 / 夏の 初めの 夜 and its translation. I think it is:
夏の: summer’s
始めの: begin’s
夜: night
i.e. a night in early summer

Waiting for the 審判 …

Hmm not sure though I do think you are more correct with “have you ever seen” as opposed to my “can you see” from 見た

Page 86.


Have you ever seen shining fireflies flying near rivers and fields in the early summer nights?


Appearing and disappearing dim lights are truly wonderful, aren’t they?


The light is placed near their butts.

p.s. English sentences can seem a bit wonky. Sorry about that, English is not my native language.


Welcome @glitchy_li! We don’t worry about our sentences sounding wonky! In fact more literal sounding translations are often more useful than ones converted to more natural English.

I don’t know if this means nights in early summer; or early during summer nights. I figured “early summer nights” is similarly ambiguous in English!

Wikipedia says they are around at twilight - so maybe early in the night during summer is right?


Page. 87

電球が ついている わけでも ないのに、ホタルは どうやって 光るのでしょう。

How does the fire fly glow even though it doesn’t have a light bulb?

実は ホタルは、体の 中で ルシフェリンと いう 光の もとを 作る ことが できます。

In reality, from within the firefly’s body, the so-called luciferin is the source of the ability to make light.

ホタルは この ルシフェリンを 使って 光るのです。

Fireflies make light using this luciferin.

では、ホタルが 光るのは、 なんためでしょう。

Then, what do you think is the advantage of the firefly glowing?

ホタルは 光で、自分の いる ところを なかまに 知らせたり、オスと メスが、けっこんするためのあいずを おくったりしていると いわれています。

It is said fireflies can signal their location to a companion, and males and females can cue to establish breeding.


p. 87

How can the firefly glow although it doesn’t have a light bulb?


In fact it can produce a light source called luciferin inside its body.


The firefly glows using this luciferin.


So what is the purpose of the firefly’s glowing?

ホタルは光で、自分のいるところを仲間に知らせたり、オスとメスが、結婚する :couplekiss_man_woman:ための合図を送ったりしていると言われています。

With the glow the firefly notifies its position to its companions, males and females are sending signals aiming at marriage.

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Well, I didn’t know fireflies got married but there it is in black and white, and a picture from Igor to prove it!

2000kanji I think you got the end of sentence 2 attached by mistake to the end of sentence 1. In my book the first sentence is the same as Igor wrote.


Of course you are right. I was probably dazzled by all these glowing fireflies. It’s corrected now.
My IME sometimes wildly copies on every click, if I do not type ENTER to choose the correct variant.

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ホタルは なぜ おしりが 光るの?

Why do fireflies bums shine?

夏のはじめの夜、川や 田んぼの そばで、ホタルが 光りながら とんているのを 見たことがありますか。

On early summer nights, near to rivers and fields, have you seen fireflies glowing as they fly?

ほのかな 光が、ついたり きえたりして、とても ふしぎですね。

A faint glow, it’s very mysterious, how it goes on and off.

光っているのは お尻に 近い ところです。

The glowing is in a place close to their bum.

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I tried to keep it extra literal for @Micki
I also took a different interpretation to the final sentence of pg 87 but I’m guessing @IgorTheGreat is right based on his photographic proof. Since it’s written in katakana I’m assuming I’m on the wrong track.

Translations pgs. 86 + 87

ホタルは なぜ おしりが 光るの?

Why do fireflies’ bottoms shine?

夏の 初めの 夜、川や 田んぼの そばで、 ホタルが 光ながら とんでいるのを 見た ことが ありますか。

The start of summer nights, near rivers and buckwheat farms, fireflies flying while illuminated is a thing to see, yes?

ほのかな 光が、 ついたり きえたりして、 とても ふしぎですね 。

The dim light, lights and goes out is an exceedingly marvelous thing, isn’t it?

光っているのは おしりに 近い ところです。

The shining is at a place near the bottom.

電球が ついている わけでも ないのに、ホタルは どうやって 光るのでしょう。

It does not mean though that a lightbulb is attached. How does the firefly shine then, I wonder…

実は ホタルは、体の 中で ルシフェリンと いう 光の もとを 作る ことが できます。

Truthfully, inside the fireflies body, called luciferin, a light source is able to be produced.

ホタルは この ルシフェリンを 使って 光るのです。

For fireflies, this luciferin is used to explain how it shines.

では、ホタルが 光るのは、 なんためでしょう。

Then the fireflies shine for what purpose?

ホタルは 光で、自分の いる ところを なかまに 知らせたり、オスと メスが、けっこんするためのあいずを おくったりしていると いわれています。

Fireflies when lit, its location is informed to companions. For men and women who marry it is said to act as a good sign.


Logically, (夏の始め)の夜 would mean the nights of early summer, and 夏の(始めの夜) would be summer’s nights of beginning, so I guess early summer wins from math point of view. And the fireflies do come up in June.

I’ve decided to give this section a try (after gaining few levels of WK and whole 30 points of N5 on bunpro), and guess what - the very first sentence is a challenge! Again :frowning: :slight_smile:


It seems to get a bit easier. I’ve done most of p87 and by that page I knew quite a few words as lots repeated. Give it a go!


I found a kindred spirit, the only translation that has “buckwheat farm”, not just generic “paddy”. I wonder why the author was so particular.

EDIT Page 86. Actually, buckwheat farm should be そばの田んぼ, not the other way around, so I guess そば means “near”, not “buckwheat” here:
夏のはじめの夜、川や 田んぼの そばで、ホタルが 光りながら とんているのを 見たことがありますか。

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Welcome back :smiley: It is still pretty challenging for me as well. Most sentences do not go untranslated! I usually will plug in words i know or should know to the translator to check for multiple meanings. Still, I am noticing a personal improvement with how I put the sentences together


Page. 88
ホタルが 光る ようすを かんさつすると、 オスと メスでは、光り方が ちがう ことが 分かります。

When male and female fireflies glow, you can observe and understand that they glow in different ways.

夜 くらく なると、 オスの ホタルは、光を 出しながら とんで、メスを さがします。

When the night becomes dark, male fireflies go in search for females while putting out patterns of light.

メスの ホタルは、 弱い 光を 出しながら、草や 木の葉の 上で オスが 来るのを じっと 待ちます。

The female firefly puts out weak light patters while waiting sitting motionless on top of a blade of grass or tree leaf and waiting for the male to come.

オスは メスの 光を 見つけると、強い 光を 出して メスに 合図を おくります。

When the male finds the female’s glow, he sends out a bright light to signal the female.

I found this page kind of challenging personally. It didn’t help my dog was having a panic attack for no reason :c


p. 88

The observation of the fireflies’ glowing state shows that males and females differ in their glowing.


When the night falls, the male fireflies produce light while flying, and look for females.


The female fireflies emit a weak light while patiently waiting on grass and tree leaves for the males to come.


When the male firefly detects the female’s glow, it sends a signal to the female by emitting a strong light.


Agree that was a tricky page! Great efforts from both of you!

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