THE SPLRMATOGENESIS OF THE SPIDER. iSl 



ing that every spermatid contains the accessory chromosomes. 

 This stage in Agalcna is shown in Fig. 38 and in Epcira, Figs. 

 4244. In all cases the chromatin assumes a crescentic form, 

 the anterior end bends in, the posterior end folds over it and we 

 see the mature spermatozoa each consisting of a crescent-shaped 

 nucleus, covered by a pellicle of cytoplasm and curled up. In this 

 condition they are found in abundance in the lumen of the testis, 

 in the ducts and in the pedipalps (Figs. 39-41). 



In Fig. 48 is pictured a spider spermatozoon after Wagner in 

 which he demonstrates a tail. This is of special interest to me 

 because I have not succeeded in finding an organ of locomotion 

 in connection with the spermatozoon. As he also worked upon 

 Agalena, I am surprised to find my results so different from his. 

 He claims that " Die Spermatozoen haben auf gewissen Stadien 

 bei alien Species einen typischen Schwanz mit Achsenfaden. 

 Der Achsenfaden bildet sich im Protoplasma der Spermatocyte 

 (resp. Spermatide) zuerst als ein kurzes Stabchen welchem 

 bisweilen einige Archoplasmakornchen anliegen. Mit dem 

 Kerne verbindet er sich erst nach dessen Umwandlung in die 

 Chromatinplatte." 



" Wo sich Achsenfaden und Chromatinplatte verbinden liegt 

 am Rande der letzeren ein Zahnchen." In striving to get light 

 upon these points I have studied the spermatozoa of about a 

 dozen different species of spiders, have stained them intra vitam, 

 have made smear preparations fixed by heating at the boiling 

 point, have studied, with painstaking care, sections fixed and 

 stained in a great variety of ways, and in no case has a tailed 

 spermatozoon been found with the exception of Pliolcns and even 

 here the elongated portion which might be looked upon as a 

 tail, stains more like a middle piece and its cytoplasmic origin is 

 questionable (Fig. 51). My belief is that the "tail" which 

 Wagner saw was nothing more nor less than the outline of a 

 vesicle which is nearly always in evidence when the spermatid is 

 being transformed into the spermatozoon, and that what he 

 describes as a little tooth is really nothing more than the anterior 

 end of the head bent under, although in this case there should 

 be a rounded bend instead of what he figures (Figs. 46, 47). I 

 would be glad to believe in the existence of a tail and have 



