SYMBIOSIS OF YEASTS 127 



else any pathogenic role. Conte and Faucheron 1 nave aiso observed 

 yeasts in the fatty tissue of female coccidia. They were led to regard 

 this observation as a sort of symbiosis. 



This hypothesis has been confirmed by the investigations of Pier- 

 antoni and Karl Sulc which, on account of their great biological in- 

 terest, are important enough to mention here. All of the authors 

 who have studied the adipose tissue of the homoptera have noticed 

 the existence in these tissues of special organs which have received 

 different names, depending on the insects in which they have been 

 observed, but which seem to have a certain simi- 

 larity; such are the pseudo-vitellius and green 

 bodies described by Huxley, Lubhock, Balbiani 

 and Henneguy in various Aphides, the polar mass 



observed by Heymons in the eggs of the Cicadides ^. 53 A Larva 



and the oval body found by Berlese in the genus of Ptyelus ' limatus 



Dactylopius. The significance of these organs has ^ mycetome M. 



. . MI B, Section of myce- 



remamed unknown until the present time. How- tome of Ptyelus line- 



ever it has been stated that they were cells with <^* ( after Karel 



contents of fat droplets or protein grains. Some 



have stated that they served to control the reserve products. 



The work of Pierantoni and Sulc, carried out independently at 

 the same time, have shown that these organs, which appear to be in 

 all of the homoptera, present the same structure and may be homol- 

 ogous. 



These organs to the number of two in each insect are situated on 

 each side of the intestines of the insect quite near the reproductive 

 organs (Fig. 53, A). They are made up of a mass of large cells with 

 a yellow or greenish epithelial membrane. They contain an ameboid 

 nucleus and a cytoplasm filled with small spherical or oval bodies. 

 These bodies, regarded by some as reserve products (fat or proteins), 

 in reality resemble the yeasts. These yeasts vary from one insect to 

 another. Budding yeasts are especially found, among which is a 

 variety already mentioned, Saccharomyces apiculatus parasiticus, 

 Schizosaccharomyces and some yeasts related to these latter to which 

 Sulc gave the name of Cicadomyces. 



These yeasts agree with those described by Lindner, Conte and 

 Faucheron in the Coccidia and are encountered constantly, probably 

 being handed down in the egg. The cells situated in the center of 

 these organs divide regularly, and cause by their growth a shattering 

 of the superficial layers which liberates the yeasts. These happen to 

 come in contact with the ovaries and penetrate the egg during the 



1 Conte, A. and Faucheron, L. Presence de levures dans le corps adipeux 

 de divers Coccides. Comp. Rend. Acad. des Sciences, 144, 1907. 



