Natural History of British Zoophytes. 337 



themselves often breed others, and those others sometimes push out 

 a third or fourth generation before the first fall off from the original 

 parent." — Trembley found in one experiment that an individual of 

 H. grisea produced forty-five young in two months ; The average 

 number per month in summer was twenty, but as each of these be- 

 gan to produce four or five days after its separation, the whole pro- 

 duce of a month was prodigious. * 



" No sooner is a young one furnished with arms, than it seizes and 

 devours worms with all possible eagerness ; nor is it an unusual thing 

 to behold the young one and the old one struggling for, and gorging 

 different ends of the same worm together. Before the arms come out, 

 and even sometime afterwards, a communication continues between 

 the bodies of the old and young, as appears beyond dispute by the 

 swelling of either when the other is fed.-]- But a little before the 

 young one separates, when its tail-end begins to look white, trans- 

 parent, and slender, the passage between them, I believe, is closed. 

 And when the young one comes away, there remains not the least 

 mark where it had been protruded."- — " After a young polype once 

 gets all its arms, it alters indeed in size, but neither appears to shift 

 its skin, or undergo any of the changes most other insects do." J 



Instead of buds or little protuberances, the body sometimes push- 

 es forth single tentacula scattered irregularly over it, and these ten- 

 tacula can be metamorphosed into perfect polypes, the base swelling 

 out to become the body, which, again soon shoots out additional ten- 

 tacula to the requisite number ! § 



This is a mode of generation which the term viviparous does not 

 correctly embrace, unless we give to that word a signification so ex- 

 tensive as to include all generations which are not oviparous : It is 

 an example of equivocal, or what some foreign physiologists deno- 

 minate, the generation by the individualisation of a tissue previously 

 or already organized, || — and seems to be the usual way of propaga- 



* Mem. pour 1' Hist, des Polypes, 174 — 5. Also Baker, lib. s. cit. 53 — 4. 



•f- By some clever dissections, Trembley demonstrated the reality of this com- 

 munication. Mem. 161 — 2. 



} Baker lib. s. cit. 50. § Baker ut cit. 110—11 : 121—3. 



|| La generation n'est pas pour cela spontanee : une generation spontanee doit 

 etre la production d'un etre organise de toutes pieces, lorsque des elemens in- 

 organiques se reuniront, pour produire un animal, une plante. Cette generation 

 est impossible, et n'a jamais lieu. Une generation equivoque est celle ou des tis- 

 sus organises prealablement par un etre deja pourvu de vie, sHndividualisent, 

 c'est-a-dire se separent de la masse commune et participent encore, apres cette 

 separation, de l'etat dynamique de la masse, c'est-a-dire de sa vie, mais, a son 

 propre profit. C'est ainsi qu'un tissu produit un Entozoaire. C'est de la vie con- 

 tinuee." — Ch. Morrenin Ann. des Sc. Nat. an. 1836, Vol. vi. p. 90. Part. Zool. 



