Dodge: Cultures of Ascobolus and Aleukia 221 



further investigation will be necessary before the identity of the 

 parasite can be determined. Portions of the mycelia of the host 

 and of the parasite are shown in Plate 72, figs. 7 and 8. 



Aleukia umbrina Bond. 



This fungus grows on burned places during the early part of 

 the season in the vicinity of New York City. The species has 

 been identified by Dr. F. J. Seaver. The outer surface is 

 coarsely warted, especially in young specimens, where the stipe 

 imbedded in the earth is also seen to be well developed. Plicaria 

 echinospora (Karst.) Rehm, has been recorded as growing on 

 burned places and the two species are apparently closely related. 



Pure cultures of this species may be obtained easily by growing 

 the spores on an agar medium made up with an extract of heated 

 soil. When the spores are heated to 70°-8o° C. for fifteen 

 minutes, as described under ''Ascobolus carhonarins" (Bull. 

 Torrey Club 39: 139-197), germination is above 90 per cent. A 

 large germ-tube is first formed and is usually followed later by 

 a smaller one at the opposite end of the spore. (PI. 72, f. 9.) 



Columbia University, 

 New York City. 



Explanation of Plate LXXII 

 Ascobolus magnificus Dodge 



Fig. I. (a) Ejected spores before drying. (&) After drying out the 

 epispore is cracked in all directions. X 525. The width of the cracks is 

 slightly exaggerated in the drawing. 



Fig. 2. (o) Ungerminated spores. (&) Germinated spore. X 525. 



Fig. 3. (a) Germinated spores. (&) A large spore much swollen. X 525. 



Fig. 4. Section through an ascocarp showing hymenial layer and the tips 

 of secondary mycelial hyphae ( ?) appearing as hairs on the exterior. 



Fig. 5. Asci and paraphyses. (a) X 100; (6) X 300, 



Fig. 6. Archicarp as it appears in youngest fruit bodies that can be seen 

 with a hand lens, (j) The stalk; (a) ascogenous cell; (0 trichogyne. The 

 size of the ascocarps at this time is indicated by the border line. X 150. 



Figs. 7, 8. (o) Mycelium of a fungus parasitic on the mycelium, {b) My- 

 celium of the 'Ascobolus. X 525. 



Aleuria umbrina Boud. 



Fig. 9. (a) Ungerminated spore, (fc) Germinated spores, (c) A spore 

 with only one germ-tube. X 525. 



