386 



mation or fission, but it can be formed only by the act of genera- 

 tion, and its play of extension by budding or by division, must 

 always be within a certain cycle, which cycle is recommenced 

 by the new act of the conjugation again of the two sexes. In 

 this way the dignity of the ovum as the primordium of all true 

 individuality, is maintained. 



In another place I have entered upon the discussion of those 

 many points suggested by these studies. One of these is, the 

 relation of this subject to some of the various doctrines of deve- 

 lopment, which have been advanced in late years, such as that of 

 Alternation of Generation^ by Steenstrup, and that of Partheno- 

 genesis^ by Owen. I have there attempted to show that the 

 phenomena of these doctrines, as advanced by their respective 

 advocates, all belong to those of gemmiparity, and that, therefore, 

 Alternation of Generation and Parthenogenesis in their implied 

 sense, are misnomers in physiology. Another point is, the 

 identity of this mode of reproduction we have just described in 

 the Aphididae, with that observed in the so-called hibernating 

 eggs of the Entomostraca, and the like phenomena observed in 

 nearly every class of the Inverlebrata. They are all referable, 

 in my opinion, to the conditions of gemmation, modified in each 

 particular case, perhaps, by the economical relations of the 

 animal. 



A report from the Committee, to whom was referred the 

 work of Mr. Girard on the Bibliography of American Natu- 

 ral History, was read and accepted. 



It was highly favorable ; strongly commending the judi- 

 cious arrangement of the work, and the thoroughness with 

 which it had been prepared, and showing it to be quite 

 indispensable to all who would become acquainted with the 

 progress of Natural History in America. 



Mr. Sprague laid upon the table a valuable collection of 

 plants from Switzerland, presented to the Society by Mr. 

 B. F. Kendall. 



