LATERAL PORES AND GLANDS 383 



be "divisible" in the spermatid into numerous parts such that when 

 they appear in the spermule they are capable of bringing about 

 "normal" syngamy. 



It will be interesting to discover how factors or genes, concepts 

 essential to clear thinking on the subject of heredity, can be imagined 

 to "carry on" through the mazes of the division that, extending 

 throughout the spermatid, gives rise without mitosis to 64 apparently 

 equivalent elements in the spermatidian tissue (see spmtd polyncl, 

 Fig. 2). The spermatidian tissues (aggregates of haploid cells, 

 gametophores Fig. 12) seem more clearly reminiscent of the alter- 

 nation of generations in plants than any animal structure hitherto- 

 made known. 



Subjoined is an alteration of the Boverian diagram illustrating 

 the spermatogenesis here described. It will be seen that in this 

 Boverian diagram (Fig. 14) the proportions of the camera lucida 

 drawing (Fig. 2) are to a large extent adhered to. The microsomes 

 and the alveolated nuclear spaces are shown with no very great 

 departure from nature. The number and size of the microsomes is 

 approximately correct and the new arrangement of the microsomes 

 around 64 centers as shown in the diagram is not violently schematized. 

 The same is true of the size, color and disposition of the chromatoid 

 bodies. For simplicity the spermatidian tissues are reduced in the 

 diagram to masses of 64 and 128 nuclei respectively. 



The features accompanying and following the oocytic synapsis seem 

 at least a gesture toward the path followed in the spermatogenesis, 

 but they have not yet been carefully studied. 



Occasion for staining the gonads of Spirina parasitifera offered an 

 opportunity for a more careful study of the unicellular glands of 

 this species that "empty" through minute pores in the cuticle of most 

 regions of the body, but particularly along the lateral fields. Uni- 

 cellular structures of this character are known to be widespread 

 among nemas, having been recorded for a great variety of free-living 

 genera and a few parasitic genera. It is not known whether the 

 various unicellular organs of this character hitherto recorded are 

 homologous or whether they are connected with a variety of func- 

 tions. The fact that they are well developed on aquatic forms that 

 experiment proved to be in urgent need of oxygen has led the writer 

 to suggest the possibility that these "glands" or some of them, may 

 be connected in some way with respiration. This would seem in 

 accord with the failure hitherto to observe any such organs in the 



