COLLYBIA VELUTIPES 473 



malformed fruit-bodies were found among a large number of normal 

 ones growing in a cluster at the base of a dead willow tree ; and 

 a week later, in the same place, ten additional plants were observed 

 showing the same malformation to a greater or less extent. 



Still another teratological form of Collybia velutipes was observed 

 by Stewart,! namely, " a robust young sporophore with four small 

 sporophores forming on the gills. The pilei of the secondary 

 sporophores were perfect in form, but almost sessile. Three of them 

 were 2 mm. in diameter, while the fourth was smaller. With the aid 

 of a hand-lens the gills were readily distinguishable. Nq evidence 

 of mutilation of the gills of the primary sporophore was detected." 

 1 2 have observed secondary sporophores on the gills of Lentmus 

 lepidevs in fruit-bodies growing on wood in the laborator}; ; and 

 Brefeld ^ has described and illustrated a similar phenomenon in 

 Coprinus stercorarius. However, Brefeld ascribes his secondary 

 sporophores to the effect of wounds made in the mother-sporophore 

 when it was very young. 



While the teratological forms of Collybia velulijjes observed by 

 Stewart concern the gills only and are not so striking to the eye 

 as the morchelloid modification described by Legue, they neverthe- 

 less afford additional evidence of the plasticity of the fruit-bodies 

 affected and of apparently autonomous changes in the usual mode 

 of morphogenesis. 



^ F. C. Stewart, he. cit., p. 85. 



2 A. H. R. BuUer, " The Reactions of the Fruit-bodies of Lentinus lejndevs to 

 External Stimuli," Annals of Botany, vol. xix, 1905, p. 434. Also cf. these Researches, 

 vol. i, 1099, p. 48, Fig. 16, I. 



^ O. Brefeld, Untersuchungen iiber Pilze, Leipzig, Basidiomyceten I, 1877, 

 pp. 72-75. 



