144 MICRO-ORGANISMS AND DISEASE. [CHAP. 



all, or only slightly, septate, and at their end form flask-shaped 

 enlargements, from which grow out radially short cylindrical 

 cells basidia; and these again at their distal or free ends 

 produce chains of spherical spores or conidia. This is a very 

 common mould, and according to differences in the coloration 

 of the mycelium and spores is subdivided into different species : 

 A. glaucus , candidus, flavescens, fumigatus, &c. 



Besides this mode of spore-formation (asexual), there is 

 another (sexual), which according to de Bary consists in this : 

 some terminal branch of the mycelium becomes twisted like a 

 spiral, this is considered the female organ of fructification or 

 carpogonium ; from the same thread branches grow towards the 

 carpogonium ; one of these branches becomes fused with the 

 terminal portion of the carpogonium called the ascogonium, 

 while the others the pollinodia branch and surround the 

 carpogonium like a capsule, the whole organ is now called a 

 perithedum. Finally the ascogonium by rapid division gives 

 origin to a number of oval septate tubes, inside of which by 

 endogenous formation numerous spores make their appearance. 



Grohe 1 was the first to show that the introduction of the 

 spores of some species of aspergillus into the vascular system 

 of rabbits sometimes produces death, with symptoms of 

 metastasis into the various organs due to localised foci, where 

 these spores grow into inycelial filaments. Lichtheim 2 showed 

 that such mycoses in rabbits cannot be produced by the spores 

 of Aspergillus glaucus, but by those of Aspergillus flavescens 

 anclfumigatus. Grawitz 3 studied this process more minutely, 

 and found, that no matter whether the spores are injected into 

 the vascular system or into the peritoneal cavity, there are 

 established in the kidneys, liver, intestines, lungs, muscles, anc 7 

 occasionally in the spleen, marrowbones, lymphatic glands, 

 nervous system, and skin, minute metastatic foci, due to the 

 growth of the spores into mycelial filaments with imperfect 

 organs of fructification, but no spore-formation. Grawitz 

 thought that the spores of ordinary moulds (penicillium and 

 aspergillus) are capable of assuming these pathogenic proper- 

 ties if cultivated at higher temperatures (39 40 C.), and in 

 alkaline media. These fungi, as is well known, grow well at or- 

 dinary temperatures and in acid media, and are then innocuous 

 when introduced into the animal body ; but by gradual accli- 

 matisation they can also be made to grow at higher tempera- 

 tures and in alkaline media, when they assume pathogenic 



1 Perl. klin. Woch. 1871. 



9 IMd. 9 and 10, 1882. 



3 Virchow's Archil', vol. Ixxxi. p. 355. 



