310 SEA-SIDE STUDIES. 



allied to Generation, does so because he maintains that the 

 oriiriual unchanged cells, which resulted from fecundation, 

 form the starting-point of the bud ; and that thus the bud 

 and seed are identical, because both really originate in iden- 

 tical cells — both really issue from an original act of fecunda- 

 tion ; whereas these pages contain abundant evidence that 

 fecundation is by no means necessary to Generation, except 

 in the higher animals ; plants, polypes, insects, and crus- 

 taceans, being generated ivithout fecundation. 



It is worthy of remark that, although the Hydra propa- 

 gates by eggs and by buds, it only produces two or three 

 eggs during the autumn, whereas it buds all the year round. 

 We may consider its oviparity, therefore, as an exceptional 

 process. I believe it is one solely detemiined by external 

 conditions, and that if the Hydra were kept in an unvarying 

 temperature, it would never produce eggs at all, but continue 

 budding to the end of the chapter. 



All the endeavours to prove that Parthenogenesis is 

 in every case the result of mere Gemmation are powerless 

 ajrainst Owen, who denies the essential difference between 

 Gemmation and Generation, and serve to support his view 

 when they are coupled with Von Siebold's discoveries. The 

 Hydra sending forth a second Hydra from its own substance 

 directly, may be said to " bud " like a plant. The Aphis 

 producing broods of Aphides internally, instead of externally, 

 which broods are unattached to their parent, may likewise 

 be said to exhibit "internal Gemmation," — although this 

 budding is the result of ova. Von Siebold's virgin moths 

 present us with eggs instead of young — eggs in every way 



