Jons. Schmidt 149 



TAHLK III. t^H X 9 7. 



Medium t«nt|trrmturr l^iw t4'iit|irr«(urp 

 Nn. of m.Tii l^im 3.1 Mhy lUirii H .Inly 



8 8 — 



7 r.» »i 



G - (I 



TABLE IV. c^6 X 9G 



same pair of parents. The date of birth of the young is noted in each 

 ca.se, iis also whether developed at low, medium, or high temperature. 



It is distinctly evident from the tables that the different broods do 

 exhibit a difference in the number of dorsal fin rays, and it is further 

 seen that the average number of rays was greater where the young had 

 been develojyed at a high temperature than luhere their development took 

 place at a low temperature. 



In all my later experiments this result has been confirmed. I will 

 content myself with di.scu.ssing a single one of the later exp<3riment.s, 

 which, technically speaking, h;ul the advantage over the preceding ones 

 in that the tempemture in the aquaria could be kept constant, there 



