CYTOLOGY OF THE MYXOMYCETES. 8 1 



structure of the spores is veiy intricate and is best brought out 

 when stained with fuchsin and methyl green. The nuclei are 

 large and faintly stained and usually present a solitary spherical 

 nucleolus which likewise stains but faintly. There is often, 

 though not always, present in the cytoplasm an irregular mass of 

 material surrounded by a vacuole. The material can be clearly 

 resolved into acidophilic and basophilic constituents, staining 

 with fuchsin and methyl green respectively. Of the two, the 

 basophilic structures are the most definite and appear in the form 

 of definite spherules suggestive in some measure of chromosomes. 

 But the occurrence of the material in vacuoles is equally sug- 

 gestive of phagocytosis, which, however, would seem to be un- 

 likely in view of the dense membrane surrounding each spore. 

 Only further study will reveal the nature of the material. Mi- 

 tochondria are distributed quite evenly throughout the remainder 

 of the cytoplasm and are characterized by their rod-like shape. 

 There is no counterpart here for the changes in the morphology 

 of mitochondria observed in Badhamia, Fuligo and Enteridium. 



No special provision is made during spore formation, or in 

 cell division generally, for an equal division of mitochondria, 

 which might be looked for if we regard them as in any sense 

 carriers of heredity. They do not, like the nucleus, change their 

 solubilities or staining reactions during spore formation. This 

 is the more interesting since the resistance of the mitochondria 

 increases progressively in the spermatogenesis of mammals. 

 There is some indication, however, that with spore formation 

 there is a tendency toward a reduction in the amount of mi- 

 tochondria with relation to the cytoplasm. 



Capillitium: 



I have not traced the formation of the capillitium from con- 

 fluent vacuoles as described by Strasburger but my observations 

 of the later stages are of interest in connection with the work of 

 Harper and Dodge ('14, p. 3). In plasmodia of Hemitrichia 

 clavata and rubiformis fixed in weak Flemming and stained with 

 either safranin, gentian violet and orange G, or with iron hema- 

 toxylin, they describe lines running toward the vacuolar tube, 

 where their centers of convergence are marked by a series of 

 granulations (see their Figs. 1-5). 



