370 DIVISION III.—MODE OF LIFE OF THE FUNGI. 
Aspergilli of this kind, one of which has been certainly determined as Asper- 
gillus fumigatus, have been found since 1815, and especially since Virchow’s more 
recent and more exact account of them, spontaneously developed in the human 
lungs and in the air-passages of birds. They find their way there no doubt, as they 
reach the ear, with the dust which mingles with the atmospheric air, and meet with 
similar conditions and adopt a similar mode of development. Gaffky and others, 
Lichtheim especially, obtained characteristic phenomena of development, in this case 
phenomena of disease, when the gonidia of Aspergillus fumigatus and A. flavescens, 
Eidam, two species distinguished by the high optimum of their vegetative temperature, 
over 37°C., were introduced by injection into the blood of animals, such as rabbits and 
dogs. On the other hand, Eurotium Aspergillus glaucus, E. repens, Aspergillus niger, 
and Penicillium glaucum, the latter of which was once unjustly suspected by Grawitz, 
were proved by similar experiments to be incapable of development in animal bodies, 
and therefore harmless. 
Lichtheim found that the facultative parasitism of the two species of Mucor 
noticed above on page 359 was perfectly analogous with that of the two species of 
Aspergillus just mentioned, with the limitation only which was also noticed before, 
that Mucor rhizopodiformis has no endophytic development in the dog. 
The spores of these Fungi introduced by injection into the blood-passages are 
carried through them into all parts of the body. It would appear that they do not 
germinate in the blood-current itself, but in certain organs of the animal into which 
they are conveyed by the blood. The living organs show different degrees of liability 
to the attack of the Fungus, especially when the spores are injected in smaller 
quantities, and Lichtheim arranges them in the following descending series for the 
Mucoreae: kidneys, Peyer’s patches, mesenteric glands, spleen, marrow, liver. 
Similar results appeared with Aspergillus fumigatus, but with less regularity and with 
a characteristic localisation of the Fungus in the membranous labyrinth. The living 
brain remained free in all cases from the development of the Fungus. But when the 
organs are dead the germination and development of the Fungi takes place in all in 
the same degree. The spores develope mycelia in living bodies, but it is only in 
exceptional cases that a fresh formation of spores takes place. The development of 
the Fungi is attended by characteristic local derangements, and these produce dis- 
turbance of the general health, for a fuller account of which the reader is referred to 
medical works* and especially to Lichtheim. 
Spontaneous Aspergillus-mycosis and Mucor-mycosis in internal organs re- 
moved from direct access of air is to say the least a doubtful occurrence. 
Many Fungi living in insects are obligate parasites. Everything of im- 
portance that is known of the development of the epiphytic Laboulbenieae which 
belong to this category has been stated at page 263. Their dissemination by 
means of the spores conveyed from one insect which has been attacked by the 
Fungus to another, especially during the act of conjugation, has been clearly described 

1 See especially Virchow, Archiv, IX (1856), p. 557,-—Fresenius, Beitr. p. 84,—Lichtheim, 
in Berliner klinische Wochenschrift, 1882, Nr. 9 and in Zeitschr. f. klin. Med. VII, Hft. 2.—Gaffky, 
Mittheil. aus d. k. Reichsgesundheitsamt, I, 526. These papers contain further notices of the 
literature of the subject. 
