246 PROCEEDINGS OF THE AMERICAN ACADEMY. 



When a portion of the hymenium containing some of the large 

 cells below the sub-hymenium was put in a sterilized Van Tieghem 

 cell in an endeavor to induce the ascospores to germinate, it was found 

 that frequently these large cells, which measure 20-25 fx in diameter, 

 sent out germ tubes, or turned brown, secreted thick walls about 

 themselves and resembled considerably chlamydospores (Figures 26, 

 27). 



Germination of the ascospore. — The mature asci are quite uniform, 

 clavate, with the apex rounded, opening by a lid, 125 /x in length and 

 15 ju in diameter at the widest place. The ascospores are hyaline, 

 spherical, 12 ^i in diameter, and arranged in a single row. At maturity 

 all the spores from each ascus are ejected with considerable force 

 blowing off the lid at the apex in a manner somewhat similar to that 

 of Ascobolus, and thus are thrown in a bunch for several centimeters, 

 and, by means of the protoplasmic material which surrounds them, 

 adhere readily to any glass surface with which they may come in 

 contact. These spores were allowed to strike a sterilized cover glass 

 and then supplied with nutrient material and cultivated in a Van 

 Tieghem cell, which had previously been thoroughly sterilized. Not 

 only were the spores alone used as just stated, but frequently a por- 

 tion of the hymenium with the asci was gouged out with a sterilized 

 platinum needle and hanging drops made of it. In an effort to get 

 these spores to germinate, various kinds of media were used, such as — 

 potato, prunes, bran, horse dung, dog dung, Spanish chestnuts, 

 carrots, etc., either as a decoction, or more often solidified with agar. 

 In spite of these varied efforts, the spores could not be made to germi- 

 nate. The writer some time ago succeeded in getting the spores of 

 Ascobolus to germinate in Van Tieghem cells by first crushing them 

 lightly between two glass slides, and it occurred to him that the same 

 method might be successful here also. Accordingly hanging drops 

 were made as before, using different media, but the spores were first 

 crushed with a sterilized platinum spatula on the cover-glass. This 

 method proved successful. These spores are composed of a thick 

 brittle episporiura and a thin flexible endosporium; the object in 

 crushing was to break the former without injuring the latter. Many 

 of the spores thus crushed were totally destroyed, and broken por- 

 tions of the episporium were scattered over the culture; l)ut in a few 

 cases, where the pressure was sufficient just to break the episporium 

 without injuring the endosporium, it was foimd that germination 

 took place in from 24 to 48 hours (Figures 22-24, Plate 1). When 

 this occurs the endospore pushes out, forming a germ tube which is 



