428 Excerpta Zooloyica : — Vegetation upon Living Animals. 



rise to various diseases. Among the most complete researches 

 on this subject are those of Bassi and Audouin on the Mus- 

 cadina, a contagious disease of the silkAvorm (Ann. des Sc. 

 Nat. 1837, 1838), and those of SchcEnlein on the contagious 

 ringworm [Porrigo lupinosa) of man. From these inquiries 

 our views respecting miasma and contagion have obtained 

 considerable elucidation, as it was possible in those cases to 

 isolate the contagious matters and to determine their vegetable 

 nature. A third fact also of this class, viz. the occurrence of 

 parasitic fungoid formations in the lungs and in the air-cells 

 of birds, has been observed by Montagu and Owen (see 

 * Annals,' vol. ix. p. 131, and vol. viii. p. 230) and more re- 

 cently by Miiller and Retzius, as has already been communi- 

 cated in these ^ Annals' for 1842. Connected with these obser- 

 vations are the following, which have been more recently 

 published. 



Dr. Hanover and M. Stilling have published several commu- 

 nications on contagious confervoid formations on frogs and 

 on the water salamander (Miill. Archiv, 1839, p. 338 ; 1841, 

 p. 279 ; and 1842, p. 73). Dr. Hanover first observed a mucous 

 efflorescence form on Triton punctata w^hich had been used 

 for dissection and had lain some time in water; on submitting 

 this efflorescence to microscopic examination, it proved to con- 

 sist of a very simple conferva. The mass was formed of nu- 

 merous more or less ramided tubes of various diameter which 

 attained the length of an inch. The cavity in their interior 

 w^as in some continuous, in others distinctly divided into 

 chambers by means of cellular partitions; it was filled with 

 innumerable black corpuscles, which swam about in the inte- 

 rior in a very lively manner and with an appearance of volition. 

 The motions induced M. Stilling to ascribe an animal and not 

 a vegetable nature to the efflorescence. He considered the 

 black corpuscles to be the eggs of a species of hair-shaped 

 infusorium which became developed in great quantity during 

 putrefaction, and believed that these eggs were transported by 

 the circulation of the blood and were thus deposited at certain 

 places, where he then supposed the tubes to be formed by a 

 secretion of fibrine, and which were, so to speak, polypidoms 

 {Keimstocke) in which the eggs attained their development. 



Dr. Hanover proved the incorrectness of this view in his 

 second paper on the subject, and placed beyond doubt the 

 vegetable nature of the efflorescence by the observation of its 

 development and the formation of sporules*. 



* The free and apparently voluntaiy motion of the sporules of many 

 algoe, fungi and lichens has already been observed so often, that it can no 

 longer be classed among the sin-prising phsenomena. Very recently Prof. 

 Goeppot in Breslau has described it in Ncmaspora incarnata, and has shown 



