256 BULLETIN 94. 



present. However, frequently the conditions are favorable for the 

 development of another form than the purely vegetative portion 

 of the plant, and either simple resting spores are developed, or if 

 sexual organs are present, then oospores. The number of resting 

 spores varies from one to ten or even twenty in large prothallial 

 cells where the botryoid fungus is well developed. The resting 

 spores occupy the central portion of the mass and are surrounded 

 by the smaller and terminal cells of the plant which now are 

 empty. The resting spores are rounded, sometimes oval, in form 

 and when mature are bounded by a very thick wall consisting of 

 three coats which are smooth, but sometimes appear roughened by 

 the closely cohering cell walls of the collapsed surrounding ter- 

 minal portions of the botryose mycelium. The portions which 

 become resting cells are always the larger and central portions. 

 They are much larger at the time of the formation of -the resting 

 spores than when the fungus is in the vegetative stage, and since 

 at first there appear to be no cell walls intervening it would seem 

 that their increase in size came chiefly from the outer and smaller 

 cells giving up to them their protoplasmic contents rather than 

 that the additional nutriment came from the cell of the host which 

 by this time is nearly exhausted. However, this point was not 

 determined. The wall of the young resting spore is at first very 

 thin and the protoplasm finely granular. The mature resting 



Explanation of Plate III. Completoria complens Lohde. 



Figs. 26-30 different plants with mature resting spores showing the vari- 

 ation in number developed in a single plant ; the resting spores surrounded 

 by the empty peripheral cells of the plant, which may have developed conidia, 

 or some of them entered adjacent cells of the prothallium, or possibly some 

 of them fed the developing resting spores. 



Figs. 31-32, younger stages in the development of the resting spores. 



Fig. 34, plant developing resting spores at the center and a conidium from 

 one of the peripheral cells. 



Fig. 35 conidium germinating ; 36, 37 and 39 germinating conidia with the 

 germinal vesicles or proembryos developed from each one. 



Fig. 40 germinal vesicle or proembryo developing the minute entrance 

 tube which pierces the wall of the cell of the prothallium, 38 showing the 

 entrance tube complete and the protoplasm having migrated to the center of 

 the cell where the rotund body is formed, 41 branching of young plant in 

 cell of host. 



Drawn with aid of camera lucida and magnified 30 times more than the 

 scale. Scale, i millimeter. 



