84 Cayley . — Some Observations on the Life-history of 
bacterium in the sporodochium of the fungus. Brzezinski (8) published 
a paper in 1903 in which he stated that apple canker was a bacterium 
and not a Nectria. This was contradicted by Aderhold ( 2 ). The present 
writer also found that typical sunken cankered areas could be induced in 
young one-year-old twigs of apple in the open, when inoculated in spring 
with macrospores obtained from a pure culture. Other inoculations with 
bacteria isolated from platings of macrospores from bark were tried at the 
same time, but the wounds healed up naturally and no ill effects could be 
seen. The inoculated portions of the twigs were enclosed, in both cases, in 
sterile glass cylinders plugged at each end with cotton-wool to prevent risk 
of infection from other sources. Various bacterial growths from platings 
of macrospores were also tried with pure cultures of N. galtigena. The 
cocci were discarded and only rod-shaped bacilli used. Tubes infected 
with spores of the fungus and bacilli at one and the same time showed that 
the bacilli developed rapidly at the expense of the fungus. Further work 
on these lines was, however, discontinued when it was found that N .galtigena 
would develop perithecia in pure culture on media containing glycerine. 
Life-history. 
The genus Necfria is placed by Saccardo in the family Hypocreaceae, 
a sub-group of the Pyrenomycetes. 
It has a complicated life-history which may be divided roughly into 
three distinct stages, which occur in the following sequence : 
1. The microspore stage, with minute elongate oval hyaline spores, 
5-7 fx x 1-2 /x, abstricted from fine hyaline mycelium, sparsely septate and 
inclined to monopodial branching (Fig/ 7). 
2. The macrospore stage, with 6—7 septate curved spores, 65-75 P x 4 “ 
5 /x, abstricted from branched conidiophores on a sorus or sporodochium 
consisting of coarse, densely intertwined, thick-walled mycelium, brownish 
red in colour when mature (Figs. 1, 4, 10a, 11, 12, 12 a, 13, 13#, 13 24). 
3. The perithecial stage, which occurs on the same sporodochium as < 
the macrospores. The red, flask-shaped perithecia contain paraphyses and 
numerous eight-spored asci. The ostiolum is raised, rather darker in colour 
than the rest of the perithecium, and is furnished with periphyses. The 
ascospores emerge through the ostiolum in the form of whity-buff tendrils. 
The ascospores, 15-21 /x x 6-8-5 M? are two-celled, with roughened walls 
slightly tinged with yellow (Figs. 2, 3, 5, 9, 14, 15, 16, 18-22). 
All these stages have been described by previous workers, but during 
the present investigation two-celled multinucleate spores have also been 
observed both in pure culture and in preparations on bark (Fig. 8). 
Unstained, these could not be distinguished from two-celled macrospores, 
hence their function, if any, could not be traced. 
