486 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
into a single central nucleus ; tlie surface of tlie contracted protoplasm 
clothes itself at the same time with a double membrane, the outer- 
most layer often displaying sculpturings characteristic of the species. 
Oosperms are thus formed, corresponding to those of Pythium or Lepto- 
mitus. When the oosperm (of Urocystis Violse or Tilletia caries) 
germinates, its nucleus passes first of all into the promycele, which then 
forms at its apex eight sporids ; as these elongate, the nucleus undergoes 
three successive bipartitions ; a daughter-nucleus enters into each 
sporid ; and these again form other sporids attached to the first by a 
slender pedicel. 
MM. P. A. Dangeard and M. Leger give a detailed description of 
the structure of the zygosperm in the Mucorini in the case of Sporodinia 
grandis. 
In the Ascomycetes ( [Peziza vesiculosa) M. P. A. Dangeard has also 
been able to detect a process of sexual reproduction, similar to that 
observed by Lagerheim in Dipodascus albidus * * * § The asci proceed from 
oosperms which result from the anastomosis of two conjugating filaments 
or gametes. In the production of an oosperm two filaments come into 
oontact ; in each of them a terminal cell containing a single nucleus is 
cut off by a septum ; these cells are the gametes ; in the process of con- 
jugation their protoplasm mingles, and the two large nucleolated nuclei 
almost immediately unite. The oosperm thus formed then elongates 
into a tube which swells up into the form of an ascus ; the sexual 
nucleus enters it and moves to its apex, and then undergoes division, 
furnishing a nucleus to each embryo or ascospore. 
Insertion of Spores and Direction of the Septa in Protobasids.t 
— M. P. Yuillemin points out that, while in some Fungi, as the Tre- 
mellinese, the spores are inserted on the apex of the protobasids, in 
others, such as the Auricularinese and Pucciniem, their insertion is 
lateral. A similar diversity occurs in basids, which may have terminal 
or lateral sterigmates, and in asci, where the ascospores may be in a 
single row, or in clusters. The lateral position of the spores may be 
considered the primitive one, corresponding to the transverse segmenta- 
tion of the thallus. The difference between the two types depends on 
an acceleration of development, and on a phenomenon of secondary 
adaptation, and does not affect the separation of the Protobasidiomycetes 
as a primary division of Fungi, consisting of the three suborders Auricu- 
larineoe, Puccinieae, and Tremellineae. 
Sapromyces (Naegelia).$ — Mr. E. Thaxter describes the structure 
and development of this rare genus of Saprolegniacem ( Nsegelia of 
Keinsch, Nsegeliella of Schroter) found on fir-cones in the state of Maine. 
It is closely allied to Phipidium, differing from that genus in the ab- 
sence of any differentiation between the basal cell of the hyphse and 
those of its branches. 
Nuclei of the Mucorini.§ — MM. P. A. Dangeard and M. Leger have 
studied the structure and distribution of the nuclei in various Mucorini 
* Cf. this Journal, 1893, p. 366. 
f Comptes Rendus, cxviii. (1894) pp. 84-7. Cf. this Journal, 1893, p. 668. 
% Bot. Gazette, xix. (1894) pp. 49-55 (1 ph). 
§ Comptes Rendus, cxviii. (1894) pp. 430-2. 
