Observations on Camarosporium Abietis n. sp. 147 



The final stage is sho%^Ti in Plate III, fig. 3, in which the only 

 remaining part of the wall forms a shallow cup which partly 

 encloses the mass of ripe spores which are held together by 

 mucilage. 



In order to verify the assumption that the spores escape in 

 wet weather vdth the mucilage derived from the fructification, 

 the folloNving experiment was carried out. A fructification 

 showing a shiny apex was carefully isolated and the bark on 

 which it was borne trimmed close up to its base. It was now 

 placed on its side close to and above a perfectly clean sHde. The 

 fructification was not allowed to touch the shde, but an extremely 

 fine jet of water was directed on to it and the water passing 

 over it collected on the slide. This water, on examination, was 

 found to contain mature spores and a verv thin mucilage sur- 

 rounding numerous oil-globules and h\'phal remnants, etc. 

 (Plate IV, fig. 7). The latter may be diWded roughlv into two 

 groups the components of both of which show advanced degenera- 

 tion : the elongated portions derived from the sporophores, and 

 the rounded ring-hke structures derived from the wall. The oil- 

 drops present were probably pre\"iously contained both in the 

 sporophores and in the hyphae forming the waU. The mucilage 

 stains readily with methvlene blue but does not take up corahin 

 soda. It is noteworthy that the great majority of the spores 

 contained in it are in the earhest stages of germination (fig. 7, c) 

 as sho\\Ti by the presence of a hght coloured area at the lower 

 end of the spore on the right (see below). 



AUescherd) and Saccardo(3) refer to the presence of a definite 

 ostiole in certain species of Caynarosporium and in others to 

 its complete absence. AUescher (p. 277) describes Catnaro- 

 sporium varium as possessing " unscheinbarer, glatter, glanzender 

 Miindungspapille " and C. Karstenii as " miindimgslos " and of 

 C. Visci Saccardo (iii, p. 463) remarks " ostiolis papillatis, demura 

 distincte perforatis." These statements may indicate that there 

 is considerable variation within the genus in this respect, but 

 it is possible that thev are the result of incomplete investigation 

 of species similar in their dehiscence to the one described here. 



In order to obser\-e the remaining sequence of events in the 

 life-history of this fimgus it is necessary to study the germina- 

 tion of the spores and to isolate the mycehum produced by them 

 in pure culture. For this purpose various hquid media were 

 tried, but the only one which proved successful was an extract 

 of Abies Lou-iana made by boiling the shoots for some time in 

 water. This extract, %\ith the addition of agar, was found to 

 form a satisfactory- medium for the further growth of the 

 myceHum. The mature hberated spores germinate freely in the 

 extract and form a germ-tube at one or both ends. The end 



