August 16, 1912] 



SCIENCE 



223 



were prepared (blood tested) for inoculation 

 and feeding with material passed through the 

 Berkefeld filter. Those fed and inoculated 

 with the filtered culture all survived, while 

 those which were treated in the same manner 

 with the unfiltered culture all died. 



It might be well to call attention to the 

 fact that caterpillars fed with the juices of 

 those which die of the disease succumb as 

 rapidly as do caterpillars fed with the pure 

 culture. The disease is probably spread in 

 nature by the juices of disintegrated cater- 

 pillars flowing over the leaves which are later 

 eaten by others. We have found Gyrococcus 

 in the fasces, and the fact that such excretions 

 are washed over the leaves by rain seems to 

 show that the disease may also be spread in 

 this manner. 



What economic value the " flacherie " dis- 

 ease may have in combating the gypsy moth, 

 we are not prepared at present to say. We 

 have no experimental evidence whatsover that 

 the disease may be air-borne, as claimed by 

 Mr. Eeiff, although, of course, we do not wish 

 to exclude such a possibility. Our experi- 

 ments seem to show, first, that it takes a good 

 many Gyrococci to kill a caterpillar and, sec- 

 ond, that conditions must be favorable for the 

 disease or, putting it in another way, unfav- 

 orable to the caterpillars by lowering their 

 vitality; so it seems very improbable that any 

 such methods as are at present utilized for the 

 artificial spread of " flacherie " will be of any 



The present race of gypsy moths in Massa- 

 chusetts seems to be permeated with the disease, 

 for we have been unable to find a single locality 

 where " flacherie " is not accomplishing some 

 good. Professor Wheeler has made many ob- 

 servations and he agrees with us as to the 

 above statement. He has been out with us on 

 many of our inspection trips and has likewise 

 noticed the great influence which temperature 

 and other external conditions seem to have on 

 the disease. Since we can not control ex- 

 ternal conditions and since the disease ac- 

 complishes so much good in nature and is 

 probably increasing year by year, and since 

 it is transmitted from mother to offspring, we 



may have to content ourselves with its nat- 

 ural havoc. 



In conclusion we append a description of 

 the peculiar bacterium which we believe to be 

 the specific cause of the wilt disease, with a 

 discussion of its generic characters. 



Gyrococcus flaccidifex gen. et sp. nov. 

 Cells in free state spherical, becoming slightly 

 oblong just before division. Division in one 

 direction of space only. After division each 

 half may be spherical or may come to an 

 abrupt tip, assuming a more or less heart- 

 shaped appearance. Frequently the two 

 halves are unequal; one half may be spherical 

 while the other may be more or less heart- 

 shaped, or slightly oblong. If cells remain 

 connected after fission, chains of three or four 

 are formed. A chain exceeding four units 

 has never been observed. Size of single cells; 

 diameter .51 ju,-.85 /x. No evidences of endo- 

 spore formation. Capsule distinct. Organs of 

 locomotion present. Gram-negative. Colon- 

 ies on agar spherical or oblong, small (diam. 

 .5-1 mm.), smooth, cretaceous. 



All of the above size and form characters 

 may vary somewhat, especially in Gyrococci 

 under cultivation. They are somewhat larger 

 after long culture on artificial media and the 

 formation of chains of three or four is much 

 more frequent. Indeed, the formation of 

 chains has never been observed in the fluids 

 or tissues of the host. We are certain that the 

 Gyrococci are motile, for when all air currents 

 are excluded from the slide with sterile vasa- 

 line and everything is quieted down as much 

 as possible, they gyrate across the field of 

 vision in all directions and with remarkable 

 rapidity. Furthermore, their behavior in the 

 living cells is such that no one would mistake 

 their activities for Brownian movement. 

 Flagellar stains were tried, but so far without 

 success. 



It will be seen from the above description 

 that Gyrococcus resembles Pneumococcus 

 more closely than any other form. Its motil- 

 ity and its negative reaction to Gram's stain 

 are, however, sufficient, we believe, to exclude 

 it from that genus and hence, owing to its 

 peculiar gyrating mode of locomotion we have 



