Miscellaneous. 



521 



allied to the mildew of wheat. A very singular part of their oeco- 

 nomy is their reproduction year after year from the same mycelium, 

 which forms discoid patches on the living stems exactly as in the 

 curious genus Cyttaria, so important an article of food to the Fue- 

 gians, it gives rise to tubercles of various sizes on the living branches 

 of various species of beech. A figure of one of the species, Podisoma 

 macropus, Schwein., was published in the volume for 1845 of Sir W, 

 J. Hooker's ' London Journal of Botany/ from a sketch by Dr. Wy- 

 man, who was so fortunate as to observe the germination. Mr. 

 Woodward forwarded to me sketches illustrative of the germination 

 from Cirencester in 1847, which confirmed the curious observations 

 of the Messrs. Tulasne on the germination of Uredinese, published in 

 the early part of that year. 



In April of the following year he was so good as to forward to me 

 a specimen of Podisoma fuscum, which enabled both myself and Mr. 

 Broome to observe the germination, and to secure sketches of the 

 various phases which were exhibited. Professor Gasparini has lately 

 published a memoir on the subject, which has not yet reached me. 



Meanwhile I am anxious to record Mr. Woodward's observations, 

 regretting that in the multitude of avocations I have neglected to do 

 so at an earlier period. The spores vary extremely in different parts 

 of the same tremelloid mass, being sometimes strongly pointed, some- 

 times perfectly obtuse ; the pointed spores, however, seem the only 



Figs. 1, 2, 3, 4, spores oi Podisoma fuscum, germinating; fig. 2 shows 

 clearly the protrusion of the cotyledonoid from the secondary membrane ; 

 fig. 5, a spore more obtuse than usual, which has not germinated ; fig. 6, 

 masses which appear to have escaped from the spores, and which eventually 

 elongate into cotyledonoid threads. [We are indebted to the kindness of Dr. 

 Lindley for the use of this woodcut. — R. T.] 



Ann. ^ Mag. N. Hist. Ser. 2. Vol. iii. 34 



