RURAL e^'gi]s;eeeing. ■ 689 



cortaiu oiroumstancos and of producing a septieeuua in chiclvons and other fowl><. 

 This occurs especially as a result of shipment. The virulence may be increased 

 by repeated passage through canary birds. The seirtieemia is thus produced 

 in move than 50 per cent of cases. The period of incubation is about 12 hours. 

 The.disease may be transmitted by contact and by feeding. Chickens, pigeons, 

 ducks, and canary birds are susceptible to artificial inoculation, and to a lesser 

 extent white mice, guinea pigs, and rabbits. 



Occasionally this disease may be mistaken for fowl cholera. In such cases 

 it is necessary to make bacteriological cultures to reach a differential diagnosis. 



A vegetable extract as a vaccine for fowl cholera, Rautmann {Berlin. 

 Tierarztl. Wclmschr., 1907, No. 29, pp. 552, 553). — A proprietary extract made 

 from a mixture of several plants and recommended as a vaccine for fowl 

 cholera was tested with the result that it showed neither protective nor cura- 

 tive value. As compared with serum treatment in parallel experiments it 

 proved to be worthless. 



Notes on experiments with, blackhead of turkeys, C. Curtice ( U. 8. Dcpt. 

 A(jr.. Bur. Aiiiiii. Indus. Circ. 119. pp. 1(1). — A series of experiments were made in 

 cooperation with the Rhode Island Station with Bronze. White Holland, Narra- 

 gansett, and wild turkeys for the purpose of determining the possibility of im- 

 munity to blackhead and the conditions under which infection takes place. It 

 was shown that turkey eggs do not carry the protozoan organism of the dis- 

 ease. Young and adult turkeys show symptoms of blackhead within 4 weeks 

 after exposure. Poultry yards apiiear to be quite extensively infected with 

 blackhead, but with proper precautions turkeys may be raised to the small 

 roaster stage with little or no loss. 



Dry sandy soils appear to be best for poultry yards. No breed of turkeys so 

 far as tested is immune to blackhead, but older birds are more resistant than 

 the young. 



Notes on parasitic nematodes, including descriptions of new genera and 

 species and observations on life histories, B. H. Ransom ( U. 8. Dcpt. Agr., 

 Bur. Aniin. Indus. Circ. ltd, pi). 7>. — Biological and economic notes are given 

 on Trichostrongylus, Ostertagia, Cooperia. and Nematodirus, the last three of 

 which are described as new. 



8trongi/1oides longus, which was observed as a common parasite of sheep at 

 the experiment station of the Bureau of Animal Industry, was found capable of 

 penetrating through the skin of rabbits, causing an infestation of the alimentary 

 tract. Infestation took i)lace as readily- through the skin as when the larvae 

 were fed to rabbits. It appears, therefore, that this parasite is transmissible 

 from sheep to rabbits either by penetration through the skin or as a result of 

 eating contaminated food. It was shown by experiment that Trichostrongylus 

 rctortwformis may be transmitted directly from rabbit to rabi)it without an 

 intermediate host. 



RURAL ENGINEERING. 



Cement pipe for small irrigating systems and other purposes, G. E. P. 

 Smith (Arizona 81a. Bui. 55, pp. i07-7.s.}, figs. 6). — This bulletin calls attention 

 to the great losses of water from open ditches in the sandy soil of Arizona and 

 recommends carrying the water in pipe lines to prevent these losses. It 

 <lescril)es the making of cement pipes for such use, giving the mixture used, the 

 cost, and the results obtained. The cost of i)ipe made of cement and sand and 

 of cement, lime, and sand is given in the following tal>le. Since the pipe was 

 made near a river where both sand and water were available no charge is made 

 for either of these. 



2;»740— No. 7— OS 7 



