84 EXPEEIMENT STATION EECOED. 



of each species recovered from the 24 dogs was A. mystax 29G, D. camnum 312, 

 and T. serrata 17. 



Hepatozoon perniciosuni (n. g., n. sp.); a hemogregarine pathogenic for 

 white rats; with a description of the sexual cycle in the intermediate host, 

 a mite (Lelaps echidninus), AY. W. JIiller (P«<6. Health and Mar. Uosp. Serv. 

 V. S., Ili/ff. Lob. Bid. J/B. pp. 51. pis. 20). — " Hepatozoon perniciosum, n. g., n. sp., 

 is a heniogregarine found in white rats in Washington, D. C, and the cause of 

 an epizootic observed among tliese animals. The protozoon Is conveyed by a 

 mite {Lelaps echidninus), which is the true intermediate host. Infection is 

 transmitted to the rat when the mite is swallowed by the rat. The mites are 

 ectoparasites upon the rats, from which they receive infection by sucking the 

 blood. Multiplication of the hemogregarine in the rat takes places in the liver. 

 In the stomach of the mite the hemogregarines conjugate and form an ookinet, 

 which penetrates the stomach wall and completes its development in the body 

 tissues of the mite." 



A new rabbit cestode, Cittotsenia mosaica, M. C. Hall (Proc. U. S. Nat. 

 Mus., 3.'f (1D08). pp. 001-600, figs. 0). — A new species of tapeworm taken from 

 a rabbit (Lcpus [Sylvilarjus] pinetis) in Colorado is here described as C. 

 mosaica. This is said to be the only genus of rabbit cestodes represented both 

 in the Old World and in America, 



The principles involved in the standardization of disinfectants and the 

 influence of organic matter upon germicidal value, Harriettp: Chick and 

 C. J. Martin (Jour. Hyg. [Camhridge], S {190S), No. 5, pp. 65//-6fl7).— Experi- 

 ments made with phenol, mercuric chlorid, and emulsified disinfectants to deter- 

 mine their effect in the presence of definite amounts of organic material are 

 here recorded. A modification in the methods commonly employed for the 

 standardization of disinfectants is suggested. A bibliographical list of 37 titles 

 is appended. 



Wounds of animals and their treatment, N. S. Mayo and W. W. Dimock 

 (Estac. Cent. Agron. Cuba Circ. 29, English Ed., pp. 15, figs. 4)- — A popular 

 account prepared for the stock owner. 



RURAL ENGINEERING. 



Clearing pine lands, E. B. Ferris (Mississippi lita. Bui. ILS, pp. 3-11, figs. 

 3). — This bulletin discusses briefiy the I'emoval of stumps from pine lands by 

 digging and cutting, burning, blasting, and pulling, and describes the devices 

 used. Other methods such as filling auger holes in the stump with niti'ate of 

 soda, kerosene, and strong acids have been tried, but are not considered practical. 



The cost of clearing 35 acres at the station in 1902 by blasting and burning 

 averaged $17 per acre, but in recent experiments on 2.3 acres of land having 

 158 stumps reipiiring boring, a simple machine was used to bore the holes and 

 then firing, this reducing the cost per acre to less than $S. The bulletin 

 includes a description of this boring machine. 



The cost of clearing logged-off land for farming in the Pacific North- 

 west, H. Thompson (U. S. Dcpt. Agr,, Bur. Plant Indus. Circ. 25, pp. 16, figs. 

 9). — This is a summary of information obtained from contractors and owners 

 in western Washington, western Oregon, and northern California. Various 

 methods of removing stumps are described, with tabulated data of costs. The 

 methods described include pulling with the donkey engine, burning, and blast- 

 ing, and these are illustrated by diagrams shov,'ing the best way to employ 

 them. There are three tables, the first giving an approximate ostiniato of the 

 extent of cultivated, timber, and logged-off lands; the second, of the cost per 

 stump of removing fir stumps; and the third of the cost per acre of clearing 



