560 EXPERIMENT STATION RECORD. 



and strong soap within a few hours after exposure, or the sprinkling of sulphur 

 in the underclothes before going into localities where chiggers prevail. Various 

 other local treatments may be applied such as soda, iodin, or alcohol, but the 

 effects are usually temporary. 



The destruction of mosquitoes in houses with pyrethruni, A. L. Herkeba 

 (Com. Pur. A[/r. [Mv.rico], ('in: -J8. pp. 5. fii/s. );?). — According to the author's 

 experience houses may be ridden of mosquitoes by the thorough use of pyre- 

 thrum. The powder is distributed by means of small hand bellows and is not 

 injurious to man even if applied in excess. 



Contributions to the study of silkworms, K. Toyama (Bui. Col. Ayr., Tokyo 

 Imp. C'liir.. 7 (1906), No. 2, pp. 225-393, pis. 7, chart i).— The author finds that 

 polygamy is a normal habit of the silkworm and that fertilization is much more 

 intiuenced by the condition of the females than by that of the males. 



A parasitic fly (TachUia no^tira) is reported as causing great losses among 

 silkworms in Siam. The egg of the parasite is laid on the skin of the silkworm 

 and the larva bores into the host. The parasite is described in its various 

 stages. It appears to be distributed throughout the Indo-Chinese peninsula, in 

 some cases from 70 to 80 per cent of the silkworms in a restricted locality being 

 parasitized. The Siamese i)rotect the silkworms by wrapping cotton cloth 

 around each worm basket, while the Chinese use mosquito netting upon windows 

 and doors. 



A long series of experiments was carried on in crossing silkworms with 

 special reference to determining whether the results conform with Mendel's 

 law. It appears that in general the color of the cocoon and the egg and the 

 various larval markings are inherited in accordance with Mendel's law, while 

 the shape of the cocoon and various other characters follow some other law. 



The length of the tongue of bees, X. Kulagin (Zool. Anz., 29 (1906), No. 

 2.'i, pp. 711-716). — A large number of measurements were made of German bees, 

 American red-clover bees, and other varieties for the purpose of determining the 

 relative length of the tongue. The tongue of dark races of bees in America and 

 Russia appears to be distinguished by its length. Careful measurements, how- 

 ever, indicate but little difference in the length of these bees and dark German 

 races. The average length of the tongue of dark bees was 6.21 mm. and of red 

 clover bees 0.22 mm., the greatest observed length Ijeing 6.60, nun. in the dark 

 bee. The average length of the tongue of Italian bees is greater than that of 

 dark bees, while the longest tongues were found in Cyprian bees, the average 

 being 0.5 mm. 



Since the length of the nectar tube in red clover is 9 to 10 mm., it is evident 

 that the existing races of bees are not capable of extracting honey from this 

 plant. 



The respiratory organs of bees, S. Dyachenko (Izv. Moscov. Selsk. Khoz. 

 Inst. (Ann. Inst. Agron. Moscon), 12 (1906), No. 1, pp. 1-lJ,, flrjs. .9).— The ana- 

 tomical features of the respiratory organs of bees are described in considerable 

 detail by way of comparison with the respiratory organs of other insects. 



The swarming of bees, Sophie Diatschenko (Ztschr. Wlss. luscldcnhiol., 

 2 (1906), No. 9, pp. 283-2SS) .—The study of the causes and means of regulating 

 the swarming of bees has always proved an interesting one to the entomologist 

 and practical bee raiser. According to the author's observations swarming is 

 more likely to occur in times of heavy or very light honey yield than during the 

 pei'iod of moderate flow of honey. The regulation of swarming may easily be 

 acconqylished by furnishing a moderate amount of room for tlie I-.c(»s of each 

 colony. 



The number of bees in a colony, .1. Devauchelle (Apicnltiiir, 50 (1906), 

 No. 9, pp. 322-326). — In estimating the weight and number of bees in a colony 



