The Development of the Ascocarp in Lachnea cretea 
BY 
H. C. I. FRASER, D.Sc. (Lond.), F.L.S. 
(Mrs. D. T. GWYNNE-VAUGHAN.) 
Head of the Department of Botany, Birkheck College , London. 
With Plates XLII and XLIII. 
Z ACHNEA CRETE A, ThiL, Is a small, pale, buff Discomycete, beset with 
' numerous darker hairs and described as occurring on plaster ceilings. 
It appeared in this laboratory in the Spring of 1912, in the course of an 
attempt to obtain material of Pyronema conjluens. In January, 1912, a Petri 
dish of 3 % agar was sprinkled while still fluid with finely powdered charcoal, 
and on it were placed fragments of charred stick known to have borne 
Pyronema conjluens in the previous autumn. Various mycelia developed, 
and some were transferred to the double medium recommended by Claussen 
(’ 12 ). 1 Pyi'onema was not found, but a few ascocarps of Ascophanus carneus 
developed, together with various Hyphomycetes, Bacteria, and Moulds, and 
the cultures were put aside. 
In March one of them showed a single specimen of Lachnea cretea . 
New cultures were started and an abundant supply was obtained. The 
fungus was grown on Claussen’s medium, and subsequently on 3 % agar 
made up with decoction of plaster both with and without mineral salts. 
Material was fixed, without removal from the agar, in various strengths 
of Flemming’s fluid and in 1 % solution of iodine in 1*5 % lithium iodide. 
Sections were stained chiefly with Heidenhain’s haematoxylin followed by 
solution of erythrosin in clove oil. Uncut material was stained in a mixture 
of strong aqueous erythrosin and glycerine, and was mounted in glycerine 
jelly. Owing to the transparency of the agar it was possible to examine 
the archicarps in their natural position. 
Unfortunately, the nuclei of this fungus are small, and cytological 
detail did not prove available. The archicarp, however, differs so much 
from that known in other members of the Pezizaceae that some account of 
its morphological characters seems to be desirable. 
1 Outer dish, 0-05 % KH 2 P0 4 , 0-05 % NH 4 N0 3 , 0-02 % MgS0 4 , o-ooi % Fe 3 (P0 4 ) 3 ; 
inner dish, as above plus 2 % inulin; in each case 3 % agar was used, instead of the 2 % recommended 
by Claussen, as it sets with greater certainty. 
[Annals of Botany, Vol. XXVII. No. CVXI. July, 1913.] 
