SPERMATOPHORES OF AMBYSTOMA PUNCTATUM. 2O9 



Compound spermatophores are not all so regular in form as 

 those figured. Sometimes successive spermatophores are packed 

 together so closely that is it difficult to distinguish individuals 

 in the complex ; but while the first impression obtained from some 

 of these spermatophores was that of great irregularity, closer 

 study showed that all of them might be reduced to the vertical- 

 serial type, the Y-shaped type, or a combination of these. 



Some of the sperm masses of the simple spermatophores, or 

 the terminal one in the case of a compound spermatophore, were 

 found considerably frayed as if from being taken up into the 

 cloaca of a female; rarely, the entire ball of sperm was missing. 

 It is of course possible that either condition might be accidental. 



In one hundred spermatophores taken at random, the number 

 of each kind was as follows: 



1. Simple type 23 



2. Compound, two in vertical series 45 



3. Compound, more than two in vertical series. 21 



4. Y-shaped, or combination of this type with (2) or (3) 11 



Total '. 100 



In none of the spermatophores examined was there any ap- 

 proach to the complexity of structure shown in European urodeles 

 by Zeller ('05). Zeller's drawings appear to me highly conven- 

 tionalized. 



Discussion. — Of the various kinds of spermatophores of 

 Amhy stoma punctatum, the simple type is functionally the most 

 perfect ; yet even this is not so highly differentiated and struc- 

 turally so well adapted for its purpose as the spermatophore of 

 Di'emyctylus viridescens. In case the of Diemyctylus, I have seen 

 almost the entire ball of sperm removed from the very slender 

 stalk by the female cloaca. In Amhy stoma, on account of the 

 thickness of the stalk affording a large surface for contact with 

 the mass of spermatozoa, this would be more difficult, and ac- 

 cording to the observations of Wright and Allen ('09) does not 

 occur — only a very few sperms, comparatively, are detached 

 and retained by the cloaca. 



The only mention of compound spermatophores that I find in 

 the literature is in the case of the axolotl, described by Gasco 

 ('81). While in many cases the spermatophores deposited were 



