49 ° Wager. — On Nuclear Division 
have been made on the nuclei of the Hymenomycetes, a pre- 
liminary account of which has already been published 1 . 
The observations were made upon two species of the 
Agaricineae — Agaricus ( Stropharia ) stercorarius , and Agaricus 
[Amanita) muscarius — and were confined entirely to the 
structure and division of the nuclei in the basidia, which, on 
account of their large size as compared with the nuclei of the 
hyphae, are much more favourable objects for the observation, 
a very difficult one in this case, of nuclear division. 
Literature. 
Until very recently observations upon the nuclei of the 
Hymenomycetes were few in number, and confined mainly 
to the determination of their presence or absence in the 
various cells of these plants. Very little was known of their 
structure and practically nothing concerning their division. 
De Bary states 2 : — ‘ It may be assumed that there is a nucleus 
always present (in the basidia) though in the smaller forms it 
has been looked for in vain up to the present time. Where 
it has been observed, as in Dacryomyces , Calocera , Corticium 
calceum , and especially in the basidia of Corticium amorphum 
... it is a spherical feebly refringent body (perhaps the 
nucleolus) lying near the centre of the cell. It is not to be 
seen in the early stages of the basidium and it disappears 
when the formation of sterigmata commences.’ Strasburger 3 
also is only able to state that nuclei exist in the cells of 
several of the Agaricineae, and that the young basidium 
contains a single nucleus, which divides into two at the time 
when the sterigmata begin to form, and then further divides 
until as many as eight may be observed in the basidium. 
A considerable advance in our knowledge of these plants 
has been made in more recent times by Rosenvinge 4 , who 
1 On the Nuclei of the Hymenomycetes, Annals of Botany, Vol. VI. p. 146, 
1892 ; British Association Report for 1891, p. 700. 
2 Comp. Morph, and Biology of the Fungi, &c., English edition, p. 64. 
3 Botanisches Practicum (1884, p. 324 and 427) ; ',1887, p. 301 and 433). 
4 Sur les Noyaux des Hymenomycetes, Ann. des Sci. Nat., Bot., Ser. VII, 
tome 3, 1886. 
