27 



peritliecia in the cowpea fungus, although the vegetative growth and 

 the rorniatiou of the micioconidia continued. This is the more remark- 

 able because on all ordinary media the fungus showed tlie strongest 

 tendency to form perithecia, even when it was unable to ripen its 

 ascospores. The results obtained are as follows: 



(1) In 92 days, on strongly alkaline beef-broth peptone agar, copi- 

 ously inoculated with fresh ascospores, there was no trace of perithecia. 

 This media consisted of two test tubes of standard nutrient agar (stock 

 82a). One of them, which contained 10 c. c. of agar, received 10 drops 

 of a saturated solution of sodium carbonate (temperature 25° C), and 

 the other, which contained 8 c. c. of agar, received 4 drops of the same 

 soda solution. Each was resteamed on 3 consecutive days. Boiling 

 with this alkali caused a heavy precipitate in each tube and a dark 

 color in the agar Avhich received the most soda. Growth appeared 

 first in the tube which received the least alkali. Neither showed any 

 for the first 3 days. On the sixth day the slant surface of each was 

 spotted all over by tlie fungus. Growth, however, in each was sparing, 

 considering the number of ascospores used and the time which had 

 elapsed. In the tube which received the least alkali the growth was 

 whiter, and there was more fungus in the air than in the other tube, 

 where the growth was mostly in the substratum. At the end of 10 days, 

 in the tube which received the most alkali, the surface was gray-white, 

 with scattered white flecks. The growth of the fungus was still mostly 

 in the substratum and was not copious enough to hide the surface of 

 the agar. The tube which received one-half as much alkali presented 

 the same general appearance. At the end of 2G days both tubes were 

 almost exactly alike ; the entire surface of each was covered with a gray- 

 ish stroma sparingly flecked with white. In other words, the growth of 

 the fungus, Avhile not so prompt as on neutral or feebly alkaline agar, 

 was not prevented by the strong alkali. At the end of 51 days in both 

 tubes the mycelium showed a marked tendency to break up into iso- 

 diametric, or nearly iso-diametric cells, constricted at the septa and 

 rounded in the middle. In both tubes microconidia were now abun- 

 dant, and it was thought that possibly perithecia might develop later 

 on, as there appeared to be tiny hyph^e-complexes in some of the 

 mycelium, which had crept up out of the alkali bed and was now grow- 

 ing on the walls of the tube. 



These cultures were started November 30, and up to January 24 they 

 were exactly alike; that is, the surface was covered all over by the 

 fungous stroma, which was grayish white and bore numerous micro- 

 conidia, but no perithecia. On this date 2 c. c. of a sterile 2-per-cent 

 solution of malic acid was pipetted into the tube which had received 

 the least alkali. In 10 days 1,500 unripe hut well- developed and bright 

 coral-red perithecia made their appearance. The whole surface of the 

 corresponding tube (alkaline agar) was covered with a grayish-white 

 sheet of fungus, mostly in the agar (stroma), and it still bore an abun- 



