Scofidd : DICTYOPIIORA RAVENELII HURT. 531 



form presence of this prominent hypha would suggest the idea 

 that it is intimately concerned with the formation of the sporo- 

 phore while also perhaps evidence that a fusion has taken place 

 at this point may be seen in the knotted condition of the hypha. 

 This gives rise to the thought that a cell fusion at this point 

 may have initiated all the resulting activities. In Fig. 9 is 

 shown a section of a small strand at the branching point and 

 the supposed evidence of fusion is here very clear. That the 

 peculiar deep-staining ability of this prominent hypha is conse- 

 quent to such a fusion is indicated by the fact that the hypha 

 cannot be traced along the strand any great distance from this 

 point. 



It is unfortunate that the technique of the material is not 

 sufficiently developed to make possible a study of the nuclear 

 phenomena at this point, for clearly the complete solution of 

 this problem must lie in the study of the nuclear processes. 



Whatever action takes place here is a matter of considerable 

 importance in the life history of the plant, for the subsequent 

 differentiation of the hyphal tissue is very complex. 



The first marked step in the differentiation of the sporophore 

 is shown in Fig. 2. The gelatinization of the area between 

 the outer and inner layers of the volva is shown at V 2 . There 

 is a somewhat indefinite integument formed about the whole 

 body by the breaking down of the hyphae at the surface. The 

 hyphse lying in the area of the stipe S also begin to be promi- 

 nent and tissue of much the same nature extends out like 

 an umbrella from the top of the stipe area. This is evidently 

 brought about by the apical growth of the large hyphae shown in 

 Fig. i. Being limited by the denser hyphae of the periphery, 

 they take a downward direction. This tissue "/>" gives rise 

 later to the pileus and gleba and there remains between this and 

 the stipe a tissue of the same structure as that of the volva. 

 The tissue of the base "^" is similar in structure to that of the 

 stipe, but closer in texture. The next important stage is shown 

 in Fig. 3. Here the different areas are fairly well marked. 

 The area between pileus and stipe is distinct, but is composed 

 of very loosely woven hypha?. It is in direct connection with 

 the tissue of the volva, but is nearly separated from it by the 

 base ".Z?," which has extended considerably. 



There becomes evident at this point an area of less tension 

 near the middle of this base and just below the stipe. This is 



