10 



first suow-wbite, then developing a pnft'ed-np, grayisli white, tongh 

 stroma which becomes thickly studded with bright coral-red perithecia 

 in about eight days from the sowing of the ascospores. Steamed sterile 

 potato has proved a very suitable medium for the growth of this stage 

 of the fungus, the perithecia becoming ripe and discharging their spores 

 copiously ill two to three weeks from the sowing of the ascospores. In 

 a number of instances the cycle from ascospores round to ascospores 

 (ripe and discharged from the perithecium) was as short a time as twelve 

 days and twenty hours. These ascospores were all taken from peri- 

 thecia found on stems of tlie cowpea. 



Perithecia have also been grown from 150 or more microconidia (PI. 

 1,7). They were isolated by the poured-plate method, the material being 

 derived from an agar culture about two weeks old which was made from 

 ascospores. The perithecia developed on five diflerent media, viz, 

 agar, banana, onion, carrot, and potato. On the first three media they 

 appeared sparingly; on the carrot and potato they were abundant and 

 appeared in about two weeks. The ripe ascospores were either shot out 

 of the perithecia against the walls of the test tubes in such numbers as 

 to make distinct brown patches or else were slowly extruded, crowning 

 the ostiolum with irregular brown balls and clumps of spores (PI. 1, 1 a). 



So far as known to the writer, this is the second time perithecia have 

 been derived from the couidial fructification of any Hyi)Ocreaceous fun- 

 gus. Brefeld and von Tavel do not record any such case. On the con- 

 trary, only three such cases are mentioned by them for the whole group 

 of Ascomycetous fungi.' Klebs has since recorded this for Eurotium 

 repens, and Hugo Gliick, in 1895 (Hedwigia, p. 254), reported it for 

 Nectria moschata, which he obtained in about four weeks from pure cul- 

 tures of the sickle-shaped conidia of Fusarium aqueductum, in water 

 and plum decoction to which oak wood and bark had been added. 

 A'ery likely Brefeld's numerous failures are to be attributed to the fact 

 that he used his "Ntihrlosung" too exclusively, i. e., did not vary his 

 culture media widely enough, so as to more nearly imitate natural 

 conditions. 



On the contrary, the conidial stage of the watermelon fungus (spore 

 taken in July from the interior of a vessel) has been cultivated for five 

 years on a great variety of media, including potato, without showing a 



' "As many yeast conidia remain under cultivation through endless generations 

 always the same, so ordinarily the spores from couidiophores yield, in pure cultures, 

 always the same conidiophore ; those of pycnidia always the same pycnidia. In like 

 manner many oidia, under certain conditions, never produce anything else than 

 oidia. Only in rare cases has it been possible to obtain the ascus fructification from 

 the spores of an accessory fruit form. Of this the Penicillium [crustaceum] spoken 

 of in the second Heft of this work remains the most interesting example. Addi- 

 tional examples are Endomyces MaynusH and Diaporthe controversa. 



"Up to the present time little is known of conditions governing the development 

 of the ascus fructification. Observations in nature frequently show its dependence 

 on a certain duration of development, on the time of year, and on a definite sub- 

 stratum."— Brefeld and von Tavel: Untersuchungeu, Heft 10, p. 349. 



