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Nachdruck verboten, 



The Origin of the Sex-Cells in Chrysemys. 



(A Reply to A, Dustin.) 

 By B. M. Allen. 



An article by A. Dustin upon "L'origine et I'Evolution des Grono- 

 cytes chez les Reptiles" appeared in the Archives de Biologie toward 

 the end of last year. The author considers the origin of these cells in 

 but one form of reptile, the turtle, Chrysemys marginata. This is the 

 same form upon which I myself studied this subject, as given in an 

 article in this periodical five years ago, "Origin of the Sex -Cells of 

 Chrysemys", Anat. Anzeiger, Bd. 29. Other features of this work were 

 treated in a later paper, "A statistical study of the Sex-Cells of Chrys- 

 emj^s marginata", Anat. Anz., Bd. 30. I wish to explain at this time 

 the plan upon which these articles were written. They were intended 

 to serve as preliminary accounts of certain phases in an extended study 

 of the development of the sex-glands of Chrysemys, just as a previous 

 article on "The embryonic development of the rete-cords and sex-cords 

 of Chrysemys", American Journ. of Anat., Vol. 5, had dealt with the 

 somewhat later phenomena of the organogenesis of the ovary and testis 

 together with their efferent ducts in this same form. It was my in- 

 tention to work upon different phases of the development of the sex- 

 glands and to publish, from time to time, rather complete summaries of 

 results, as certain portions of the work were completed. I wish to 

 maintain that these preliminary accounts were not hastily drawn up in 

 advance of a thorough study of the subjects treated, but were given out 

 only after a large mass of material had been thoroughly studied in a 

 most painstaking fashion. It was then my intention to still further add 

 to this work, and to illustrate it with a large series of figures drawn 

 and executed in a more elaborate fashion than was necessary in the 

 preliminary papers. Alas for intentions ! I became more especially inter- 

 ested in the source of the sex - cells in other forms, as Rana, Amia, 

 Lepidosteus and Necturus. As a result, my plans for a more pretentious 

 work upon the entire development of the sex-glands of Chrysemys have 

 been abandoned for work that is, for the moment, more attractive to me. 



This long digression was made to show the reasons for the rather 

 sketchy nature of these papers, although, after all, brevity may not be 

 such a serious defect in the writing of a scientific paper. I have 

 nothing for which to apologize in the accuracy of my results. 



This recent paper by Dustin is very well illustrated and a large 

 part of his results are given in some detail. For both of these cha- 

 racteristics, Dustin deserves our thanks, and I most gladly express my 



