MISCELLANEOUS COLEOPTERA. 45 



matogonia, one being very small and forming with a larger one an 

 unequal pair which remained condensed during the growth stage and 

 separated into its larger and smaller components in the first sperma- 

 tocyte mitosis. The result of maturation, as in the other species here 

 described and in Tenebrio molitor, is dimorphism of the spermatozoa. 

 The method of synapsis in Coptocycla is like that described for 

 Chelymorpha argns. 



HEMIPTERA HOMOPTERA. 

 Aphrophora quadrangularis. 



The abundance of Aphrophora at Harpswell, Maine, in June and 

 July, 1905, suggested that it might be well to examine at least one 

 more of the Hemiptera homoptera for comparison with the many spe- 

 cies of Hemiptera heteroptera which have been recently reexamined 

 by Wilson ('05, '05 , '06). 



The larvae only were collected, as they gave all the desired stages 

 for a study of the spermatogenesis, and also oogonia and synizesis 

 and synapsis stages of the oocytes. In the first collections the testes 

 were dissected out, but the many free follicles break apart so easily 

 that the later material was prepared by cutting out the abdominal seg- 

 ments which contained the reproductive organs, and fixing those 

 without dissection. The same methods of fixation and staining were 

 employed as for the Coleoptera. Hermann's safranin-gentian method 

 was especially effective with this material. 



In Aphrophora the follicles of each testis are free, forming a dense 

 cluster, each follicle being connected with the vas deferens by a short 

 duct. The very young follicles are spherical, the older ones ovoid in 

 form. The primary spermatogonia (plate xiv, fig. 237) — very clear 

 cells with a lobed nucleus which stains slightly — occupy the tip of 

 the follicle. Next to these comes a layer of cysts of secondary sperma- 

 togonia which are conspicuous for their deeper staining quality (fig. 

 238). There appears to be no plasmosome in either class of sperma- 

 togonia. Figure 239 is the equatorial plate of a secondary spermato- 

 gonium. There are 23 chromosomes, two of which are conspicuously 

 larger than the others and evidently form a pair. The odd one is one 

 of the three next in size. 



Next to the secondary spermatogonia are cysts of young spermato- 

 cytes, whose nuclei show a continuous spireme and an elongated 

 deeply staining chromatin rod which is the odd chromosome (fig. 

 240). This is often more elongated than in the figure and more or 

 less wormlike in appearance. A pair of smaller chromatin masses may 

 sometimes be detected at this stage, and are readily found a little 



