STUDIES ON INSECT SPERMATOGENESIS. 333 



division that without some familiarity with the particular genus 

 one happens to be observing it is impossible to say off-hand 

 whether the division is that of a first or second spermatocyte. 

 The fate of the dictyosomes in the telophase of the second matu- 

 ration division will be taken up in connection with the formation 

 of the sperm. 



To summarize the behavior of the Golgi apparatus in these 

 stages : ( i ) in the early spermatocytes the Golgi apparatus con- 

 sists of a number of scattered bodies which in later spermato- 

 gonial generations are collected around (and in?) the mitochon- 

 drial cap; (2) during the growth-period these bodies spread 

 throughout the cell, and take part in its general growth; (3) 

 they are finally accurately oriented with respect to the first matu- 

 ration-spindle apparently through the influence of the centrioles; 

 (4) then, having undergone autonomous fragmentation, the re- 

 sulting dictyosomes are actively distributed during the matura- 

 tion division under the visible control of the centrioles, (5) by 

 which means each spermatid receives an accurate quarter of the 

 Golgi apparatus present in the first spermatocyte. 



III. The Formation of the Sperm. 



So intricate and extended are the processes by which the 

 mature sperm is differentiated from a spermatid, that at this 

 time I can scarcely do more than indicate the main features, em- 

 phasizing a few points of special interest. The great variety of 

 technical methods employed have brought to light many new fea- 

 tures in the spermatogenesis of these Hemiptera, a few of which 

 may be mentioned, but in the main they must be left for treat- 

 ment in a later paper. 



The general topography of spermiogenesis has been worked out 

 on Murgantla, chiefly because the small size of the cells offers 

 many advantages in studying the later stages, where at best the 

 sperm heads are inconveniently long. The transformation of the 

 spermatid nucleus into the sperm head has been described for 

 Euschistus by Montgomery ('n) who carried his study to a 

 stage which he called a mature sperm, describing the head " as a 

 thin hollow cylinder of chromatin, containing a distinct cavity 

 filled with nuclear sap." From his figures and his statement that 



