32 



FUNGALES. 



[Thallogen's. 



nature are the Gu^pes v^g^tantes of the West Indies ; the Muscardine, which is so 

 destructive to silkworms, and on which so many excellent ^Memoirs have been written ; 

 the mould, which so often causes the death of the common house-fly in autumn ; and 

 above all, the curious instances which have been recorded of the development of moulds 

 in the mucous membrane of the viscera of vei'tebrate animals, and in certain cutaneous 

 disorders m man. 



Mouldmess, for instance, has been fomid by M.Deslongchamps on the internal surface 

 of the au--cells of an Eider-duck while alive ; and Mr. Owen observed a similar growth 

 in the lungs of a Flamingo. — Ann. Nat. Hist. viii. 230. Col. Montagu had previously 

 remarked it in the same situation in the Scarp-duck. — lb. ix. 131. Gruby observed the 



even where the little grub which produced them has vanished, the total absence of all parts of fructi- 

 fication will at once decide the point. If, for instance, the cup-shaped gall, which is so common on 

 OcTk leaves, be the object in question, any one who has once examined the hjanenium of a Peziza, and 



observed the fructifying cells arranged vertically like the 

 pile of velvet, with their row of eight mostly elliptic 

 sporidia, cannot for a moment be deceived. It does, 

 however, sometimes happen that galls are extremely 

 like Fungi ; a remarkable instance of which has been 

 figured in the Transactions of the Linnean Society. It 

 was sent by Mr. Macleay, from Cuba, on the leaf of some 

 plant of the Natural Order Ochnaceas. In this case 

 there is not merely an extraordinary development of the 

 external cellular tissue, but the gall is formed within the 

 substance of the leaf, and after a time bursts through 

 the skin, and presents a little ovate body with a crenate 

 border, and within this an operculum which is perforated, 

 I or at least apparently perforated in the centre, so as to 



present a very close resemblance to some strange para- 



Fig. XVI. 



Fig. XYII. 



site. And, as if to make the resemblance to some Fungus more close, the gall appears to make an abor- 

 tive attempt to penetrate the opposite surface of the leaf, almost exactly in the way which is observable 

 in the curious production which is sometimes so injurious to Pear-trees. But even in this case, 

 where there is no trace of the inclosed grub or pupa, the texture of the walls of the gall is so different 

 from that of Fungals that it can scarcely deceive, on any moderately accurate examination. 



•-There is vet another production, referred to Fungals by Bernhardi, and after him by Fries and others, 

 which, hovi'ever, is probablv to be regarded neither as a disease nor parasite. These are the tuberous 

 bodies so common on the roots of leguminous plants. Their exact nature and use at present is not 

 known : but a Memoir on them has been prepared some time by M. Desmazieres. They appear a very 

 few days after the germination of the seeds, and are accompanied by a little bed of vessels, in which they 

 are nestled. At an earlv stage of gi-owth, the contents of their cells become blue, when treated by iodine, 

 which is not the case when their pulpv contents have acquired a salmon-coloured hue, when in some 

 cases the granules are simple and oblong, in others forked. There can be little doubt that they are 

 of some importance to the plant, though thev are not, like common tubers, destined for the reproduction 

 of the species, as thev pass through the phases of vegetation in a short time, and soon become rup- 

 tured and discharge their contents. No insect has ever been observed in them, nor indeed does it at 

 all appear that they are of the nature of galls. It is possible that in very dry situations, and in time 

 of drought, the nutriment collected in them is serviceable to the plant ; but this is very doubtful. 



Fig. XVI.- Galls on the leaf of an Ochnaceous plant. 



Fig. XVII.— AVoolly Oak-gall, produced by Cynips Quercusramuli.— (CwrKs.) 



