Notes on Recent Literature. 
360 
discovered. Brefeld regards this fungus as a simple member of 
the Hemibasidii, which approaches the Tilletiaceae on the one 
hand, and on the other shows a transition to the Autobasidio- 
mycetes, as the simplest form of which it may be provisionally 
accepted. A similar fluctuation in the number of the basidiospores 
can he recognised in some of the lower Hymenomycetes, viz., the 
Hypochnacese, and Exobasidium. 
Finally, Brefeld surveys the occurrence of chlamydospores in 
both the higher and the lower Fungi, and points out the close 
agreement throughout in the conditions of their formation. A new 
species of Chlamydomucor — C. macrocarpus — is described and 
figured, which when grown in nutrient solutions, forms an abun¬ 
dance of large thick-walled chlamydospores in the course of its 
hyphae to the exclusioirtof sporangia. But, when cultivated on a 
firm substratum, e.g., bread soaked in beer-wort, the formation of 
chlamydospores is entirely suppressed. When the chlamydospores 
of Chlamydomucor are kept in a dry condition they are able to 
retain their power of germination for several months. 
The occurrence of chlamydospores is a rare phenomenon in the 
Ascomycetes, but they are frequently found in the Basidiomycetes, 
especially in the Hemibasidii and Uredineas, where they form a 
regular phase in the life-history. They reach their highest expres¬ 
sion in the Uredineas in which they exhibit three distinct forms. 
Although oidia are frequently found in the higher Autobasidio- 
mycetes, chlamydospores are seldom met with. In one species, 
however, which Brefeld has named Irpicium ulmicola, there was 
an abundant formation of chlamydospores in the hyphae forming 
the tissue of the hymenophore. The phenomenon of pleomorphy, 
so far as it is met with in the Basidiomycetes, is due principally to 
the production of chlamydospores. 
(2) It has been shown by Dangeard, 1 Harper, 2 and Lutmans 3 
that in several species belonging to both the Ustilagineae and the 
Tilletiinese the young spores possess two nuclei, while the mature 
spores are uninucleate ; but the means by which the binucleate 
condition was brought about had not been ascertained. All three 
observers were of opinion that the fusions which commonly take 
place between the sporidia produced by the germinating chlamydo¬ 
spores are of a purely vegetative character. Federley, 4 however, 
claims to have seen in copulating sporidia the passage of the 
nucleus from the one cell through the connecting canal into the 
other sporidium, which he regards as a sexual process. 
Rawitscher’s researches were carried out principally with 
Ustilago Maydis and U. Carbo. In the former species no copu¬ 
lation takes place between the sporidia or the cells of the 
promycelium. The hyphal cells contain each a single nucleus. 
The binucleate condition arises by the disappearance of the trans¬ 
verse wall between two neighbouring cells of the hyphae in the 
1 Dangeard, P.A. “ Recherches sur la reproduction sexuelle des Cham¬ 
pignons.” Le Botaniste, 1893, p. 240. 
2 Harper, R.A. “ Nuclear Phenomena in Certain Stages in the Develop¬ 
ment of the Smuts.” Trans. Wisconsin Acad., Vol. 12, pt. 2, 1899, p. 475. 
3 Lutmans, B.F. “ Some Contributions to the Life History and Cytology 
of the Smuts.” Trans. Wisconsin Acad., Vol. 16, pt. 2, 1910, p. 1191. 
4 Federley, H. “ Die Copulation der Konidien bei Ustilago Tragopogi 
pratensis." Finsk. vet, Vorhandl., Bd. 46, Heft 2, 1903-4, p. 1. 
