BLAKESLEE. — SEXUAL REPRODUCTION IN THE MUCORINEAE. 263 



frequent accompaniment of Peniclllium and bacteria, contrasts were 

 made on paste in small slenders which were kept iu the warm oven at 

 26''-28°C. It may be said, however, in this connection that, although 

 infections of Rhizopus are frequent in the laboratory in cultures at all 

 exposed to the air, yet out of between 1500 and 2000 pure tube cultures 

 of different mucors, which the writer has made during the present year 

 in the laboratory where cultures of this species were constantly being 

 opened to the air, only three tubes have shown contaminations by 

 Rhizopus. The chances, therefore, that an admixture of laboratory 

 strains with the material received had possibly occurred may be disregarded 

 in view of the precautions taken. 



TABLE X. 



Arraxgemext of Strains according to Sexual Character. 



(-) 

 Jamaica Plain, Mass. (I) 



Bread 

 Jamaica Plain, Mass. (2) 



Bread 

 New Haven, Conn. (2) 



Bread 

 Lansing, Mich. (1) 



Bread 

 Lansing, Mich. (2) 



Sweet potato 

 Austin, Texas 



Bread 

 Nassau, Bahamas 



Bread 

 Cambridge, Eng. 



Berne, Switzerland 



Bread 

 Nancy, France 



Quince 

 Catania, Sicily 



Pistachio nuts 



(3) 



Neutral. 

 Brookline, Mass. (2) 



Bread 

 Brookline, Mass. 



Bread 

 Winthrop, Mass. 



Bread 

 Middletown, Conn. 



Bread 

 Granville, Ohio 



Bread 

 Breslau, Germany 



Halle, Germany 



(+) 

 Brookline, Mass. (IJ 



Sweet potato 

 Worcester, Mass. 



Bread 

 New Haven, Conn. (1) 



Baked beans 

 Washington, D. C. 



Bread 

 Delaware, Ohio 



Bread 

 Madison, Wis. 



Bread 



Honolulu, H. I. 



Plant roots 

 Margarita, Venezuela (1) 



Nuts 

 Margarita, Venezuela (2) 



Nuts 

 Caracas, Venezuela 



Dog dung 

 Port au Prince, Haiti 



Dunsr 



Repetitions were made when there was a suspicion that absence of 

 zygospores might be due to bacterial infection or to other conditions 

 unfavorably affecting the growth, and those cultures in which zygo- 

 spores were not produced under the circumstances mentioned were 



