FUNGI. 89 



in the stem, and their spores are large and oval, while the 

 latter have no capsule, granules almost always appear in 

 the stem, and -the spores are small and round. The former 

 descend into the hair-follicles, the latter ascend from the 

 roots of the hair to the epidermis. 



Not alone the skin, but the mucous membrane affords 

 a field for the growth of cryptogamous plants, at the ex- 

 pense of the health of that membrane. In the Oomptes 

 Rendus for 1842, M. Gruby describes a fungous plant, 

 which seemed to be the cause of the aphthae which so often 

 annoy sucking children, and are not unfrequently a tor- 

 ment to older persons. So minute is this plant, that each 

 little conical elevation of the milk thrush is composed of a 

 multitude of these vegetables, each having its leaflets, 

 branches and sporules. The roots are implanted in the 

 cells of the epithelion, and the spores are not more than 

 the one-ten thousandth of an inch in diameter, or about 

 a third of the diameter, or a ninth of the volume of a 

 blood-globule.* 



Vogel, in the same year, discovered vegetable Paras in 

 the aphthae, and found their organic covering capable of 

 resisting the action of the water of ammonia and strong 

 acetic acid. 



Dr. Berg, a Swedish physician, has since treated this 

 subject more at large, and shown that these aphthous pro- 

 tophytes are propagated not only from mouth to mouth, at 

 the usual temperature of the body, but that they can live, 

 and effect a reproduction out of the body, and at lower 

 temperatures, when placed in contact with substances con- 



* The nucleolus in the cell-germ frequently appears immeasurably 

 small, or even entirely escapes the eye with the highest magnifying power, 

 yet it probably serves as an introduction to the whole formative process. 

 Schleiden. 



8* 



