ASPERGILLUS FU MI GAT US 



1027 



are absent, and only mycelial threads and roundish or oval yeast- 

 like bodies are seen. 



The various species may be differentiated with difficulty as follows, 

 or cannot be differentiated : — 



A. Green species : — ■ 



I. Spores 5 microns and more. Can hardly be differentiated — 

 Repens, Flavus. 

 II. Spores less than 5 microns: — 



[a) Lives saprophytically — Fumigatus. 



(b) Not known to live saprophytically: — - 



1. Very pathogenic for rabbits — Malignus. 



2. Found in bronchial s'^xxtwm—Byonchialis. 



B. Blackish-brown species — -Nigrescens. 



C. Golden, brownish, gold- brown, or reddish — Flerbariorum. 



Aspergillus fumigatus Fresenius, 1775. 

 This is the commonest Aspergillus, and is very often found on 

 various cereals, straw, hay, etc. On solid media it produces a 

 brownish-black culture if the medium is alkaline or neutral, greenish 

 if the medium is acid. The mycelial filaments are more or less 

 ramified, the breadth varying between 2 and 3 ju,. The conidio- 

 phore hyphse are much thicker than the mycelial tubes, being, on the 

 average, about 5 in breadth. The sterigmata, which are situated 

 very close together, are 6 fi long; the conidia are roundish, 2*5 to 



Fig. 530. — Aspergillus fumigatus Fig. 531.- — Aspergillus br on- 



Fresenius. chialis Blumentritt. 



(After Blumentritt.) 



Pathogenicity. — This Aspergillus is the species most frequently 

 found in man, giving rise to an aspergillosis of various organs. The 

 spores are very resistant. Perchloride of mercury is the antiseptic 

 which has the greatest destructive action on the spores. The effects 

 on the human organism are due, in addition to mechanical action, 

 to toxins secreted by the fungi. Lucet has found in cultures of 

 A. fumigatus in Raulin's liquid a pyrogenic substance; Ceni and 



