MICKOSCOPIC INVESTIGATION. 81 



MICKOSCOPIG CENTENNIAL COLLECTION OF FUNGI. 



We propose to publisli, from time to time, in the monthly and annual 

 reports of the Department, copies of the water-colored drawings of the 

 centennial collection of microscopic fungi, edible and poisonous mush- 

 rooms, textile fibers, &c., comprising the exhibit of the Microscopical 

 Division of thisDepartment. As this collection was made under the super- 

 vision of some of the most noted cryptogamists of Europe and America, 

 and represent some of the most common types of fungi, it is believed it 

 will prove of great interest to students of botany generally, and partic- 

 ularly to the instructors of botany in the schools and colleges of agri- 

 culture of the United States. 



We make our first selection, blue mold, Fenicilliwn crustaceiim, from 

 a class of common molds which are frequently found on moldy bread 

 and other articles of food, and appear of various colors, blue, green, 

 red, yellow, white, black, &c. Blue mold (P. glaucum) is supposed to 

 have intimate relations to fermentation: a represents the appearance of 

 this fungus to the naked eye on a piece of bread; &, tuft enlarged; c, 

 threads enlarged, 420 diameters; (Z, apex x 620; e, chain of spores 

 further magnified; /, spores germinating. 



CoNiOMYCETES USTILAGINEL— l7sfiZa<;ma is the name given to a 

 family of Coniomycetes fungi related to the Uredinei, generally dis- 

 tinguished by their growing in the interior of the organ (especially the 

 ovaries and anthers) of flowering plants, causing deformity, absorption 

 of the internal tissue, and its replacement by a pulverulent substance 

 consisting of the spores of the fungi. In the earlier stage, the infected 

 orgin exhibits either a grumous mass, or an interwoven filamentous 

 mycelium, from which acrogenous spores arise; finally, the mycelium 

 disappears, and a dark-colored (often fetid) powder remains, composed 

 entirely of the spores, which are simple. 



Ustilago segetum, a genus of Vstilaginei, frequently found on cereals 

 and grasses, forming the blight called smut of corn, commonly infesting 

 wheat, oats, barley, and other grasses, filling the ears with a black 

 powder of smooth spores about -^o^ of an inch in diameter, in corn 

 sometimes about twice as large in the varieties attacking species of 

 Bromus. The smut of maize, U. maidis, has minutely echinate spores 

 liwQ ^^ ^^ mch. in diameter. Sedges are infested by JJ. olivacea with 

 olive-colored spores. U. antherarum, growing in the anthers of Caryo- 

 phyllacex, has violet- colored spores. Many other species are described 

 by Tulasue.* 



PHYLLOXEEA. 



The following letter, accompanied by specimens of the grape p7iyZZo^em 

 was addressed to the Commissioner of Agriculture by Dr, C. Jaqueme, 

 of France : 



Maeseillks, Sqrteml&r 25, 1876. 

 To the Commissioner of Agriculture : 



Sir : I have the honor to send yon, by post, some specimens of the Phjlloxera vasta- 

 irix and some of the grape-roots which have been attacked by that insect ; of the rav- 

 ages of which, in Franco particularly, you are well aware. It is alleged, I believe 

 unjustly, that we are indebted to your country for this destructive evil, the Phylloxera 

 having been brought to this country in the first importation of American vines. By a 

 comparison of our insects with yours, you can judge whether they are the same species. 

 Please send me Some specimens of your Phylloxera, and give me the particular habita 

 of the insect. 



The habits of ours are as follows : 



1. During the summer, tbe wingless females remain about four months upon the roots. 



* See Micrographic Dictionary. 

 6 A 



