172 



Several figures would seem to indicate that one of the larger cells of an 

 early stage divides and gives rise to the groups of smaller cells in a later 

 stage. This can scarcely be the case, since the number of cells in the 

 earlier and later stages are about equal, unless a number of the earlier cells 

 atrophy or are resorbed. The loss of four cells, two in the gill region, and 

 two in the region of the fifth body somite, is probable, but even with the 

 addition of these, the number of cells in the last stage examined does not 

 exceed the average number in early stages when the cells are quite large. 

 The reduction in size can, therefore, be explained only by supposing that 

 the individual cells are reduced in size during development. It would be 

 interesting to consider here the causes that lead these sex-cells to again 

 grow and divide. Since, however, this process does not begin in the stages 

 under consideration, this matter must be left till later stages are examined. 



Biological Stations. By Cakl H. EKiEXMAXN. 



The early naturalists noted briefly the animals and plants they saw at 

 home or abroad. A few centuries later they added figures to their enumera- 

 tions. Later still skins were preserved, and last of all the whole animals 

 were preserved, gathered into large museums, where they soaked and rotted 

 twenty- five years, perhaps, before some one came along to study them. 

 Some of our ornithologists and conchologists, and even some ichthyologists 

 have not yet passed beyond this skin stage in their development. Many 

 others, on the other hand, have passed this last stage and have ceased to 

 contt-nt themselves with the catalogueing of specimens and now stud^-^ the 

 method, whys and wherefores of the things about them. 



This school was established when .Johannes Midler first dipped a net for 

 pelagic animals. When it was found that the hows, whys and wherefores 

 could best be studied in the lowest creatures, naturalists flocked to the sea 

 shore, at first during their vacations. As methods for study increased and 

 apparatus multiplied permanent Marine Biological Stations were evolved. 

 First of these were the Naples Zoological Station and Agassiz's School at 

 Penikese, both established in 1873. The aims of the two were slightly 

 different. The Naples station was for original investigation. The Penikese 

 school it was hoped would awaken an interest in zoology in America. There 

 are now a large number of stations along the P^uropean coast, some large 

 and some small, but it is not the intention to speak of these. 



