“In future,” said Jack, “I shall take care not to tread upon a weed, lost, being hurt, it should scream.”

“On the other hand, they have not been found to possess any other sign of this supposed sensibility.  All their other functions seem perfectly mechanical.”

“Ah then, father,” exclaimed Jack, “you are a believer in my system!”

“We make them grow and destroy them, without observing anything analogous to the sensation we feel in rearing, wounding, or killing an animal.”

“But the fly-trap, father, what of that?”

“It is no exception.  The fly-trap seizes any small body that touches it, as well as an insect, and with the same tenacity; hence, we may readily conclude that these actions, so apparently spontaneous, are in reality nothing more than remarkable developments of the laws of irritability peculiar to plants.”

“It does not, then, spring from a family feud, as Jack supposed?” remarked Willis.

“Besides,” continued Becker, “if plants really existed, possessing what is understood by the term sensation, they would be animals.”

“For a like reason, animals without sensation would be plants.”

“Evidently.  Moreover, the transition from vegetable to animal life is almost imperceptible, so much so, that polypi, such as corals and sponges, were for a long time supposed to be marine plants.”

“And what are they?” inquired Willis.

“Insects that live in communities that form a multitude of contiguous cells; some of these are begun at the bottom of the sea and accumulated perpendicularly, one layer being continually deposited over another till the surface is reached.”

“Then the coral reefs, that render navigation so perilous in unknown seas, are the work of insects?”

“Exactly so, Willis.”

“Might they not as well consist of multitudes of insects piled heaps upon heaps?”

“It is in a great measure as you say, Willis.”

“Not I—­I do not say it—­quite the contrary.”

“Well, Willis, you are at liberty to believe it or not, as you think proper.”

“I hope so; we shall, therefore, put the polypi with Ernest’s stars and Jack’s admirals.”

“So be it, Willis; but to resume the subject.  There is a remarkable analogy in many respects between the lower orders of animals and plants, the bulb is to the latter what the egg is to the former.  The germ does not pierce the bulb till it attains a certain organization, and it remains attached by fibres to the parent substance, from which, for a time, it receives nourishment.”

“Not unlike the young of animals,” remarked Willis.

“When the germ has shot out roots and a leaf or two, it then, but not till then, relinquishes the parent bulb.  The plant then grows by an extension and multiplication of its parts, and this extension is accompanied by an increasing induration of the fibres.  The same phenomena are observed as regards animals.”