CHAPTER VIL PHENOMENA OF VEGETATION. PARASITES. 379 



shooting from them, especially from their basal portion, so that the whole was palmately 

 lobed in form; these clubs, or also, as is stated, portions of them delimited by 

 transverse divisions, may then be regarded as spores (' gonidia, conidia '), the 

 sprouting or branching of which may give rise to a new plant. On the other hand 

 we must not forget the round bodies which are sometimes found in the inner cavity 

 and which may be spores, nor the occurrence of small plants which consist almost 

 entirely of the slender filaments and the origin of which from the sprouting of the 

 clubs is not fully explained. But all this still leaves us in entire ignorance of the real 

 history of growth. 



The failure of the attempts which have been made to cultivate Actinomyces 

 outside the body of an animal, supposing always that it is really a plant, leads 

 naturally to the assumption that it is an obligate parasite. But even this may be 

 doubtful. From the experience of the pathologists who relied chiefly on the local 

 occurrence of the swellings, it is probable that the surface of the mouth and throat 

 and in some cases small wounds on them are the parts where the presumed parasite 

 makes its entry and attacks the animal, and that it is conveyed there with the food. 

 Johne frequently found in the pockets of the tonsils of pigs, even when the animals 

 were quite free from actinomycosis, small bits of plants rough with spikes, such as 

 bits of the awns of grain and the like, and Fungus-bodies resembling growths of Actino- 

 myces attached to them in considerable quantities. Further investigation is required 

 to explain the true meaning of all these observations. 



A peculiar disease known as the madura disease, which is endemic in some districts 

 of India and causes dangerous swellings and degeneration in the feet and hands, has 

 been ascribed to a parasitic Fungus, named by Berkeley Chionyphe Carter! 1 . More 

 thorough investigation has shown that it is at least doubtful whether there is any causal 

 connection between the disease and the growth of a Fungus. Fungus-elements are 

 found, but not invariably accord ing to more recent accounts, in the swellings, and there 

 is no ground whatever for supposing it to belong to the form obtained by cultivation on 

 rice-pap which bears the name of Chionyphe. It is hard to say what this Chionyphe 

 itself is. 



The often described occurrence of Fungi in eggs is a special case of saprophytic 

 vegetation, and is not therefore one for consideration here. 



PARASITES ON PLANTS. 

 a. Facultative parasites. 



SECTION CVIII. Parasites on plants display much greater variety in their 

 adaptations to their peculiar mode of life than those which live on animals. 



A quite gradual passage from saprophytes to parasites is effected especially by 

 the facultative parasitism of certain saprophytic Moulds which cause rottenness in 

 orchard fruits ; the softening of pears, it should be observed, is not due to the 

 action of a Fungus. These phenomena were investigated by Davaine 2 in 1866, and 



1 H. J. Carter, in Ann. mag. nat. Hist. IX (1862), p. 442, and in Journ. Linn. Soc. VIII, 1865. 



M. J. Berkeley, in Jourri. Linn. Soc. VIII, 1865. 



H. V. Carter, Mycetoma or the fungus disease of India, London 1874. 



Hirsch in Virchow's and Hirsch's Med. Jahresber. X, I (1875), p. 437, XI, I (1876), p. 382. 



Lewis and Cunningham, The Fungus Disease of India, Calcutta 1875. 



" Recherches sur la pourriture des fniits (Comptee rend. 83, pp. 277, 344). 



