184: 



THE MICROSCOPE. 



compact and firm network, and on each is seen the egg- 

 shaped capsule or seed-pod." 



Fungoid diseases among our growing crops attracted 

 but little attention until the mischief produced by them 



Fig. 103. Section of a Grape. 



became serious ; and the microscope has enabled us to de- 

 termine and grapple with the destroyer in its variety of 

 forms ; thus, we have our corn-crops withering under the 

 blighting influence of the Uredos and Pucinias, our vines, 

 &c., under that of the Oidium, our esculents under the 

 Botrytis infestans (potato blight), and the same disease in- 

 fects the tomata, fig. 102. 



The microscope has revealed to us that many of the skin 

 diseases attacking the human frame are but other forms of 

 the same growth of parasitic fungi, Cryptogamia, a low 

 form of plant presenting at first simple filaments, then 

 ramified, consisting of a single elongated cell, or several 

 cells placed end to end, as in those of the yeast-plant. 

 The disease known as Ringworm, infesting the heads of 

 children, is one out of forty- eight different species of 

 Cryptogamia. The conditions of growth of this low form 

 of vegetable life on the human^body are the same as in 

 other situations. Dr. Gudden, who has lately published a 

 work upon Cutaneous Diseases caused by " Parasitic 

 Growths" describes Ringworm under the name of Porrigo- 

 fungus ; the spores of which are round on the upper, and 

 filamentous on the under surface. Whenever the healthy 



