380 EXPERIMENT STATIOIST EECORD. [Vol.43 



Color defects in butter, O. V. IIvnzikfm (N. Y. Produce Rei\ and Amer. 

 Crcamcru, J,7 (1919), Nos. 19, pp. 702, 704; 20, pp. 75.',. 756, 758, 760).— Tho jiuthor 

 presents an extended summary of published experimental work on color defects 

 in butter, drawing the following? conclusions as to cause of color defects: 



" Unevenness in color, mottles, waves, and streaks are due to uneven distribu- 

 tion of the sm^ill and large liquid drops In butter, the localized small droplets 

 producing the opaque, 'thick,' dense, and whitish dapples and the large droplets 

 producing the clearer and deeper yellow blotches. The localization of the 

 small and large droplets is due to incomplete solution of the salt and uneven 

 distribution and lack of emulsion of the brine, causing migration of water and 

 brine in the butter at rest and consequent running together of the free water or 

 brine into larger drops, which produce the clear, deep blotches, and the exposure 

 of the localized fine droplets which show up as opaque, ' thick,' whitish dapples." 



VETERINARY MEDICINE. 



Principal poisonous plants of Canada, F. Fyles {Canada Expt. Farms Bui. 

 39, 2. set:, 1920, pp. XI +112, pis. 8, figs. 9^).— Brief descriptions given of the 

 more important poisonous plants found in Canada are accompanied by illustra- 

 tions, eight of the plates being in colors. The accounts include the common 

 names of the plant, a description of it, its distribution, poisonous properties, 

 symptoms, remedy, and means of control. A bibliography of two pages and a 

 subject index are included. 



St. John's wort and its effects on live stock, S. Dodd (Agr. Gaz. N. S. 

 Wales, 31 (1920), No. 4, pp. 265-272) .—The experiments here briefly reported 

 show that St. John's wort contains a principle, most abundant in the flowers 

 and flowering stems, which, when the plant is consumed by an animal, becomes 

 absorbed into the system and renders unpigmented or white skin peculiarly 

 sensitive to sunlight, with the result tliat on exposure to the sun such skin is 

 injured, as evidenced by the i-eaction. The reaction is much more than mere 

 sunburn, especially as the condition is not seen in similar animals exix)sed to 

 greater sunlight but not fed on this or other skin-sensitizing substances. In 

 addition to the skin affection, St. John's wort appears to exert an effect upon 

 the central nervous system, usually causing great mental depression but at J| 

 times excitement, which sometimes becomes almost mania. 



The biological relationships of ascarids, B. Schwaktz (Jour. ParasitoL, 6 

 (1920), No. 3, pp. 115-123). — This is a report of experiments undertaken with 

 the view of determining whether Aseoris lumbricoides which occurs in man can 

 be differentiated by means of immunological reactions from A. lumhricoides 

 which occurs in the hog. 



" The blood serum of rabbits immunized to salt-solution extract of A. ^: 

 lumhricoides (from swine) causes the formation of precipitates when added 

 to salt solution extracts of various ascarids (Ascaris, Belascaris, Toxascaris, 

 Ascaridia). The precipitin reaction as applied to extracts of these parasites 

 is, therefore, a group reaction. By the use of proper dilutions, heavier and 

 more rapidly-appearing precipitates are produced when rabbit serum immunizeil 

 against A. lumhricoides is added to salt solution extracts of A. lumhricoides 

 tlian when it is added to similar extracts of other ascarids. Extracts of 

 species of the same genus (A. lumhricoides and A. equorum) show less differ- 

 ence in that respect than extracts of worms belonging to different genera 

 (Ascaris, Belascaris, Toxascaris, Ascaridia). The results of the precipitin 

 testfe correspond, therefore, to the zoological relationships of these parasites. 



" Extracts ol A. lumhricoidc.'< from man do not appear to be distinguishable 

 from extracts ol A. lumhricoides from swine so far as the results of the pre- 



