^20 Journal of Agricultural Research voi. xiii. no. lo 



the Bureau of Entomology oi the United States Department of Agricul- 

 ture has approached all of the other parasite-introduction work. The 

 attempt is merely being made to introduce another foreign parasite which, 

 if it becomes established and becomes as effective in the woods as it is in 

 the laboratory, will prove highly beneficial. It should be added that when 

 an epidemic of the new disease breaks out in the laboratory the per- 

 centage of mortality far surpasses the percentage of mortality in a labora- 

 tory epidemic of wilt. Every one familiar with the subject knows that 

 wilt has been a very important factor in saving the New England forests 

 from utter ruin. If, therefore, the matter is approached in the spirit of 

 "parasite introduction," the economic use of insect diseases assumes a 

 new light and should prove extremely fruitful in combating many of our 

 noxious pests. 



Contrary to expectations, the field experiments have proved highly 

 successful in so far as the introduction and recovery of S. disparis is con- 

 cerned. In other words, the disease has been reproduced in the field. 

 Indeed, in two localities in Massachusetts — namely, Sherbom and North 

 Carver — it was possible to produce quite a severe epidemic. Notwith- 

 standing the encouraging results, however, no statistics will be given 

 until another season has passed. A large amount of work is still needed 

 to determine the relative importance of this method of combating the 

 gipsy moth. 



Streptococcus disparis, n. sp. 



Morphology. — From 1.5 per cent neutral nutrient agar. From 1.5 per cent neutral 

 potato agar. From milk. From neutral nutrient bouillon. 



Organism examined in these media after 24, 48, and 72 hours, after one week, and 

 each month for eight months. No decided variations in morphology observed. 

 Division occurred in one direction of space. Chains of 3 to 4 units frequently seen 

 in liquid media. Diameter not i M. Capsulated. Motility O. Gram-positive. 

 Stains readily. Typically a streptococcus. 



Nutrient agar stroke, 1.5 per cent. — Neutral. Growth in five days at 35° C. 

 scanty, beaded, flat, glistening, smooth, white, opaque, odor absent, butyrous, 

 medium unchanged. 



Potato agar stroke, 1.5 per cent. — Neutral. Gro'y\th in five days at 35° C. 

 abundant, spreading, flat, glistening, smooth, white, opaque, odor absent, butyrous, 

 medium unchanged. 



Potato. — Growth moderate, spreading, flat, odor absent, butyrous, color of medium 

 unchanged. 



Gelatin stab. — Growth best at top. Line of puncture beaded. No liquefaction. 

 Medium unchanged. 



Nutrient broth. — No ring, no pellicle, clouding slight, clearing after 15 days, 

 slight sediment, odor absent. 



Milk. — Coagulation delayed. Extrusion of whey. Color of medium unchanged. 

 No peptonization. 



Litmus milk. — Acid, prompt reduction, coagulation delayed, extrusion of whey, 

 no peptonization. 



Dunham's peptone solution. — Clouding very slight. Growth poor. , 



