146 LOUISE B. WALLACE. 



recognize its resemblance to a typical spermatozoon. In the 

 transformation of the spermatid, he incorrectly explained the 

 growth of the axial filament, holding that it first appears in the 

 cytoplasm and later makes connection with the nucleus and he 

 was also mistaken in believing that a portion of the nucleus takes 

 no part in the formation of the spermatozoon head and later dis- 

 appears. Wagner's work, on the whole, added much to our 

 understanding of the peculiar spider spermatozoon and made a 

 foundation for the more detailed work of Bosenberg which is 

 reviewed below. 



Montgomery's work ('05) on Lycosa follows in some detail the 

 history of the spermatocytes, and as a number of my results 

 differ from his, it seems worth while to enumerate the main points 

 in which we disagree. A careful perusal of his text and figures, 

 and my own observations on several different genera including 

 Lycosa, lead me to believe that he has misinterpreted some points 

 and that a further study of Lycosa will bring about greater har- 

 mony in our results. 



1. In Lycosa, he says : " There is no rest stage at any period 

 of spermatocytic history." 



In Agalena, well-marked rest stages occur in both of the 

 spermatocytes and in the spermatids. 



2. In Lycosa " where the ends of two conjugated chromo- 

 somes come together is frequently found a slight notch or break 

 which is a connecting band of linin." 



In Agalena the point of union is marked by a greater accu- 

 mulation of chromomeres at the bend of the spireme loop. 



3. In Lycosa "the split in the prophase (of the first division) 

 does not extend through the distal ends of the generally V- 

 shaped loops." 



In Agalena the split extends throughout the length of the 

 loop. 



4. In Lycosa the longitudinal split of the prophase of the first 

 maturation division becomes " in some of the chromosomes a 

 little wider than during post-synapsis but this happens with 

 only a minority of the chromosomes in any nucleus and it is not 

 a definitive stage in the structural change of every chromosome 

 for the reason of its relative infrequency. Most of the chromo- 

 somes are straight or bent rods." 



