150 Transactions of the 



of the dermatologists ; the matted condition of the hair peculiar to 

 the Pohsh people, hence termed Plica Polonica ; the " fur "-like 

 exudation from the hodies of flies ;* the " mould" of gold-fish ;t and 

 many others more or less known, but too numerous to mention. 



But while for the most part the vegetable microscopical para- 

 sites have a location on the surface of the body, it by no means 

 follows that the internal organs are free from them. On the con- 

 trary, they abundantly flourish in the whole length of the alimentary 

 canal. 



Besides many well-known varieties developed in the mouth, 

 gut, &c., one peculiar form from the stomach, Sarcina ventriculi,X 

 has been described by the late Professor Goodsir § and others. 



It may be remarked, that in the greater number of instances 

 where minute vegetable organisms attach themselves to interior 

 parts and organs, these have directly or indirectly communication 

 with the atmosphere; and hence their production is accounted for 

 by aerial conveyance of the spores. 



A fresh interest accrues in those cases where epiphytes arise 

 within closed cavities of the animal body, and as it were spring hap- 

 hazard from dense living tissues. Does such phenomena bear upon 

 those doctrines of "spontaneous generation" which have been so 

 noisily bruited of late ? At all events, here the mode of entrance of 

 the germs, their subsequent development, botanical characters as 

 elucidated by the microscope, relations in different animals, tissues 

 attacked whether primarily diseased or caused by the parasitical 

 implantation, are all questions of fundamental importance. 



Perfectly aware of shortcomings and how many problems re- 

 main to be solved as respects the life history of these cryptogamic 

 plants in deep-situate vital parts, I yet do not hesitate to place on 

 record some limited observations en jpassant. This, partly to give 

 a faithful anatomical sketch of the vegetation in situ (a desideratum 

 in cases of kind), and partly to stimulate others to further researches 

 in a field truly within the sphere of the members of this Society. 



Three instances have come under my own immediate inspection, 

 in which a vegetable-like mould has been developed within the 

 thoracico-abdomiual cavity of members of the feathered tribe; 

 and the position and microscopical characters of which I herewith 

 describe. 



1. An adult male specimen of the Great White-crested Cockatoo, 

 Cacatua cristata, Linn., was received in exchange by the Zoological 

 Society, on the 9th May, 1868, and died on the 6th June following. 



* See Dr. Ferdinand Cohn's admirable memoir, 'Empusa muscse und die 

 KranklR'it dcr Stubcnflicgen.' 



t Dr. Hughes Bennett, ' Eoy. Soc. Edinb.,' vol. xv., p. 284. 



X Placed by Robin, ' Vege'taux Parasites,' under the genus Merismopcedia of 

 Meyin. 



§ ' Edinb. Med. and Surg. Journ.,' 1842, p. 430. 



