SOS SEA-SIDE STUDIES. 



except in formal cand quite accessory details. Do not, how- 

 ever, suppose that, in denying the relative marvellousness of a 

 phenomenon which has excited so much astonislmient, any 

 attempt is made to lessen the original marvel. When the 

 rise of a feather in the air is explained by the same law of 

 gi-avitation which explains the fall of the quill, no mystery is 

 dissipated by this reduction of two seemingly contradictory 

 facts to one law. In like manner, the eternal mystery of 

 Keproduction remains the same dark Dynamis, baffling all 

 comprehension, although by its laws we may also explain 

 this novel phenomenon of Parthenogenesis, 



Hitherto physiologists have admitted three forms of Eepro- 

 duction. 1. Thejissiparous ; e. g. when a cell spontaneously 

 divides into two cells. 2. The (/e7nmiparous ; e. g. when a 

 plant puts forth buds, or a polype sends forth poh^oes from 

 its stem, 3. The oviparous ; e. g. when the plant and animal 

 ]iroduce seeds and eggs. Fission, Gemmation, and Genera- 

 tion, are the three names designating these processes. The 

 two first are universally admitted to be identical processes ; 

 but almost all writers regard Gemmation and Generation as 

 two essentially distinct processes. Owen denies that there 

 is any essential distinction. The Hydra, as he remai'ks, pro- 

 duces Hydrae both by Gemmation and Generation. " The 

 young Hydra from the bud is identical in organic structure 

 Jind character with that which comes from the ovum ; and 

 when the effects of organic development are the same, their 

 efficient causes cannot be ' altogether distinct ; ' only the 

 non-essential accessories of the process may be the subject 

 of variation." And Dr Alexander Harvey reminds us on 



