594 NATHAN FASTEN 



St. George ('92) found an interesting case of hermaphroditism 

 in the testis of Astacus fluviatihs Fabr., which he collected dur- 

 ing the months of July and August. The testis of Astacus 

 fluviatilis, as already described by Huxley, consists of an in- 

 numerable number of spheroidal vesicles, the so-called acini, 

 which are attached like grapes to the ends of short stalks, formed 

 by the ultimate ramifications of the vasa deferentia. The cavity 

 of each vesicle is at first filled with large nucleated cells near the 

 walls, the spermatogonia, which, during the period of active 

 proliferation in July undergo rapid development, so that the 

 testis grades from spermatogonia in the upper region to sper- 

 matozoa in the lower extremity near the vas deferens. Generally, 

 each acinus or vesicle bears cells in the same stage of proliferation. 



Nutritive cells are also to be found which stain heavily and lie 

 in a syncitium of protoplasm near the spermatogonial cells. They 

 are also found scattered promiscuously among the other cells 

 of the testis. 



Interspersed between the spermatogonia, St. George found 

 very large cells containing yolk material. These were egg 

 cells, and he regards them as having originated from pri- 

 mordial germ cells which have forsaken their normal path of 

 spermatogenesis, thus growing enormously in size and forming 

 oogonia. St. George also discusses the origin of the nutritive 

 cells, and states that these are derived from the spermatogonial 

 cells. 



Brandes ('97) studied the spermatozoa of Galathea strigosa 

 and found that the nucleus contained two substances, (1) an ery- 

 throphylUc substance and (2) a cyanophyllic substance. The 

 latter stains blue with methylin blue, while the other (erythro- 

 phyllic), forms a plate within the cytoplasm and stains red with 

 acid fuchsin. 



Mrazek ('01) described interesting abnormalities in the mitotic 

 divisions of the testicular cells of Astacus. Tripolar and even 

 eight-polar spindles were found to occur. In normal mitotic 

 division ninety-six chromosomes were found distributed over 

 the whole equatorial plate of the spindle. 



