BLAKESLEE. — SEXUAL REPRODUCTION IN THE MUCORINEAE. 235 



to A. sepfakt, and Figures 42-45 and 47 would place tlu3 species also in 

 the horaothallic group. We know with certainty that one species of 

 Absidia (A. caerulea) is heterothallic, but this is not a necessary indica- 

 tion that van Tieghem's description of the two species just reviewed is 

 inaccurate, for we have a similar condition in the genus Mucor, where, 

 although the species are predominantly heterothallic, yet homothallic 

 forms are known to exist. It is unfortunate that these two species have 

 not been found by other investigators. 



Absidia caerulea Bainier. 

 Mucor Sacoardoi Oudemans. 

 Froabsidia Saccardoi (Oud.) Vuillemin. 



According to Bainier ('89) the zygospores are obtained during the 

 warm season, whenever the substance upon which the fungus develops is 

 laid on a more or less thick layer of a moist absorbent material. Thus 

 ''zygospores are always obtained in abundance" when the Absidia is 

 cultivated on bread which is laid on sphagnum, " excelsior," carrot slices, 

 or wood bark. 



Oudemans and Kouiug ('01, p. 13) found this species in February on a 

 separation culture, of forest humus made on nutrient gelatine. Zygo- 

 spores and azygospores are figured. Professor Oudemans has pronounced 

 a specimen of the writer's zygosporic Absidia sent him to be identical 

 with his Mucor Saccardoi, and M. Bainier has likewise identified the 

 same fungus with his Absidia caerulea. He writes that it is common in 

 the environs of Paris on substances that decay in the woods, and that it 

 is remarkable for the ease with which the zygospores may be obtained. 

 The writer has often found the species on decaying agarics, chestnut 

 burrs, acorns, etc., and together with its zygospores on a culture of 

 rabbit dung. So far as is known it was first found in the United 

 States by Professor Thaxter at New Haven, in 1889, in mixed cul- 

 tures, and has been several times found by him from various localities 

 in New England, where it appears to be common. 



The species is heterothallic. 



Pseudo-Absidia vulgaris Bainier. 

 According to Bainier ('03), " zygospores are sometimes found in horse 

 dung cultures in the lower part of the substratum." The zygospore 

 figured gives no information in regard to the suspensor connections. 



