ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 251 



and developed a fungus like that which had been sown. The original 

 green colour of this culture became later yellow, then reddish-yellow, 

 and at last red, and now contained abundant bright yellow perithecia. 

 De Bary determined this fungus to be the typical Aspergillus glaucus, 

 the Eurotium {Aspergillus) glaucum of de Bary. Eespecting the earlier 

 mentioned larger but also non-pathogenous form, he is doubtful 

 whether it is a distinct species or only a variety of the ordinary 

 Aspergillus glaucus. Further examination of the smaller pathogenous 

 form led the author at last to this conclusion, that it is identical with 

 Aspergillus fumigatus Fres,, which is more often found in the tracheae 

 of men. That the genuine Aspergillus glaucus can be pathogenous in 

 the trache£e of birds, while to rabbits it proves innocuous, is not to 

 be denied. It is indeed certain that mould-fungi, like Schizomycetes, 

 affect different species of animals in entirely different ways. Earlier 

 observers were as little able as Grawitz to produce pathogenous 

 effects in rabbits ; the writer was therefore led to assume that they had 

 worked with Aspergillus fumigatus. In the experiments of Grawitz 

 this explanation was all the more plausible, as no exact description was 

 given by him of the fungi employed, and it is difficult to distinguish 

 the green patches of the latter from Penicillium. Lichtheim concludes 

 without hesitation that the results of Gaffky must also have been ob- 

 tained from Aspergillus glaucus. It became evident, however, that he and 

 Gaffky had arrived at the same results with different fungi. Gaff ky's 

 fungus was not Aspergillus fumigatus. This fungus was yellowish- 

 green, and therefore easy to distinguish from Penicillium. The conidio- 

 phores, sporangia, and sterigmata were more than double as large as in 

 Aspergillus fumigatus. The sterigmata were conical or flask-shaped, 

 like those of A. glaucus, the spores were also considerably larger than 

 those of A. fumigatus (6-7 /a), faintly shining, and of a clear yellow, 

 while the envelope was thin and covered with delicate wart-like 

 excrescences. Perithecia were not observed, and when old the culture 

 assumed a yellowish brown colour. Dr. Eidam has pronounced the 

 fungus to be Aspergillus flavescens, a form which has likewise been 

 observed to be a parasite in the ear. 



The main results of the author's communications are these: — 

 Up to the present time he has discovered two pathogenous forms 

 amongst AspergilU, one yellowish (A. flavescens), and the other greenish 

 [A. fumigatus), both of which were already known as parasites. The 

 pathogenous AspergilU are, however, probably not yet exhausted ; there 

 must be yet one more pathogenous form with blackish patches 

 which attacks mankind. All the mould-fungi observed by him, - 

 including the pathogenous, are species which retain both their 

 morphological and physiological properties. Further, there are fungi 

 which flourish most luxuriantly in alkaline fluids and at a high 

 temperature, but which are not pathogenous. Finally, amongst the 

 mould-fungi, as amongst the Schizomycetes, certain kinds are patho- 

 genous to one animal which are harmless to another. Unequivocal 

 proofs of this fact are yielded in the treatment by Lichtheim of 

 other genera of mould, belonging to the Mucorini, the diseases caused 

 by which will be considered in another article. 



