ii^Trs»^<> 



)^ 



^/f 



£. 



e. 



"^Wos out 



of 



H 



^SlOll 



r 



^een in ,u 



or 



VJ 



^r or fi; 



mk 



-ee 



a'- 



' -'d at the 



'"-'^ *^)- are di,b 

 -3'S ^at, instead o 

 '^orm embn-os 

 lessed the 



L globular fioiire 



^ 

 ^ 



^L^ 



escape si 



O"^) 



the tentacles, are 

 Dver their w 



or two occasions, 



arent animal 



• time that embriw 



e^-'-aping. 

 Cohn has also 



IS 



ped in a cantj 



a 



ich ^as 



I 





^^th the e# ^ , 



the e** ; 



\n 



ithout 



cife 



kno 



^ r > ••' 



D 





_H ■ I » 



>;■■ 







APPENDIX D. 



• » ■ 



cm 



r 



— when the parents were still only half 



their natural size. 

 2. The whole substance of the nucleus 

 may undergo successive segmentations, 

 so as to be entirely converted into 

 embryos. The number of embryos pro- 

 duced is, however, very variable, not 

 only in different species, but, accord- 

 ing to Lachmann^, even in the same 



species. The size of the embryos is 

 always inversely proportionate to their 

 number. 

 b. Animals encysted and stationary. 



Single, or several successive embryos, ma} 

 be produced within a cavity occupying 

 the situation of the nucleus. 



This mode of origin of embryos has been de- 

 scribed by Stein as occurring in Chilodon 

 cucullus. The embryo differs much in 

 appearance from its parent, and is precisely 

 similar to Cyclidimn glaucoma. Indi- 

 viduals of all sizes undergo the process of 



w 



encystment, and embryos of proportionate 

 size may be produced in any of them. 

 After having given birth to one or more 

 embryos, some Chilodons, according to 

 Stein, pass from their quiescent into an 



active state. 

 The production of Acinetce, as one of the 

 stages in the developmental history of the 



4 



Vorticellina, also takes place by the pro- 

 cess of which we are now speaking. This 



r ( 



4 



Ann. of Nat. Hist./ 1857, vol. xix. p. 332 



