LINNEAN SOCIETY OP LONDON. xlv 



a matter of discussion since the time of Micheli. Micheli, Bul- 

 liard, Klotzsct, and Corda all agreed in attributing sexual func- 

 tions to them. Phoebus, in the 19th volume of the ' Nova Acta,' 

 disputed this notion ; and the question seems now to be set at rest 

 by the observations of M. de Seynes in his recent work, ' Essai 

 d'une Flore mycologique de la region de Montpellier et du Gard.' 

 The conclusion at which M. de Seynes arrives is, that these cys- 

 tidia are nothing more than organs remitted to vegetative func- 

 tions by a sort of hypertrophy — that they are in fact basidia 

 which, having become hypertrophied, have resumed the character 

 of vegetative organs, as one sees abnormally a carpel become a 

 leaf. 



In a paper* published in the 'Botanische Zeitung' for August 

 26, 1864, M. Sollmann has attempted to show that in certain spe- 

 cies of Nectria a process of impregnation takes place similar to 

 that which has been noticed in Fucus, Spliceroplea, VaucJiet^ia, 

 and other kinds of Algae, viz. by the incorporation of spermatia 

 with the young spores. Much doubt has been thrown upon these 

 observations by the subsequent remarks of Professor Janowitsch 

 in the Botanische Zeitung for May 12, 1865 f, who maintains 

 not only that the so-called spermatia are not impregnative bodies 

 and do not amalgamate with the spores, but that they in fact 

 originate from the spores themselves, being the product of the 

 germination of the latter. M. Sollmann' s theory would no doubt 

 require a considerable amount of confirmatory evidence before 

 mycologists would be williug to accept it ; but, on the other hand, 

 it is almost equally difiicult to admit M. Janowitsch's suggestion, 

 that the occurrence witliin the ascus of the bodies called by Soll- 

 mann spermatia (as observed by Mr. Berkeley and by De Notaris) 

 is to be explained by reference to the process of germination. 



The cause of the disease known as " Spot" in Orchids, of which 

 several different kinds have been noticed by cultivators, has been 

 traced by Mr. Berkeley, in one instance, to the occurrence of a 

 minute parasitic fungus belonging to the genus Leptothyrium. A 

 description of the disease, with excellent illustrations, giving the 

 general appearance of the diseased leaves and a magnified figure 

 of the parasite, has been given by Mr. Berkeley in the 1st part 

 of the new series of the Journal of the Horticultural Society. 



* " Beitrage zur Anatomie und Physiologic der Sphseriaceen," von August 

 Sollmann. 



t " Ueber die Entwickelung der Fructifications- Organe von Nectria," von 

 Alexia Janowitsch. 



