25S PROCEEDINGS OF THE AMERICAN ACADEMY. 



Usually there is no differentiation between the cortical and central 

 cells, hut in old bulbils several empty cells, which may or may not 

 be colorless, are often found loosely attached to the periphery. The 

 central cells are often larger than the more superficial ones, but this 

 is not always true, since in many instances they are perfectly uniform 

 throughout. These bulbils are usually developed from a lateral 

 branch which divides up into short cells. These produce short 

 secondary branches (Figures 27, 29, 30, Plate 2) which also divide up 

 into short cells and may produce others by a process of gemmation. 

 Sometimes the primordium consists of a group of intercalary cells 

 (Figures 28, Plate 2, and Figure 14, Plate 3) which may produce other 

 cells by budding in a manner somewhat similar to that of M. papil- 

 lata. At maturity the bulbils are irregularly spherical, about 70- 

 140 p. in diameter, but where several intercalary cells have taken part 

 in its formation, the long axis frequently measures ISO /x. This bulbil 

 may be distinguished from M. ■papUlata or M. ccrvicula by the fact that 

 the cells are usually homogeneous throughout, while in the latter two 

 there is a more or less definite cortex. The margin is also often more 

 irregular in the bulbil under consideration as is shown in Figure 15, 

 Plate 3. In the immature bulbils which show this uneven outline 

 more markedly than the mature ones do, there sometimes appear 

 short branches of two or three seriate cells which extend beyond the 

 others. 



The perithelium. — In an effort to induce this fungus to produce the 

 perfect form, it was grown on various kinds of media. Decoctions of 

 potato, bran, corn meal, Spanish chestnuts, etc., were hardened with 

 agar-agar, some hard, some soft, but nothing except variations in the 

 size and development of the bulbil could be obtained. Finally, after 

 removing the shells of some fresh, sound chestnuts, the kernels were 

 sliced up and used for cultures. On this medium perithecia were 

 produced in abundance. These are almost spherical in form and vary 

 from 300-400 n in diameter, no ostiole being developed until they are 

 nearly mature, at which time a few cells about the opening form a 

 definite, though inconspicuous papilla. Terminal setae are wholly 

 absent, and only rarely do the superficial cells produce lateral filaments. 

 Frequently, however, short projections are observed from some of the 

 cells that compose the papilla, as if an attempt were being made to 

 produce setae. The perithecia are light yellowish-brown in color, 

 much lighter than that of the bulbils, and so translucent that the 

 spores can be readily seen grouped together in a black mass in the 

 center (Figure 12, Plate 3). 



