754 EXPERIMENT STATION RECORD. 



Rats in Martinique, P. des Grottes {Jour. Agr. Trop., 3 {1903), No. 29, pp. 330- 

 iiSj'l.—ln Martinique ]>('rh:ips the most important animal enemies of sugar cane are 

 rats. Notes are given on (lie Iial)its of these animals and means which have been 

 foimd more i)r kw effective in i)r('venting their ravages. 



Experiments in destroying mice in barns and mows by means of tlie organ- 

 ism isolated from susliks, S. S. JMehesiikowsky {Cenlbl. Bakl. u. Far., 1 Alt., 

 Ori</., .!,'> {lUO.i), Xo. ^jy^/^.J-J-oV;).— The destruction of mice in barns and haymows is 

 considered to be in some respects more diflicult than the control of these animals in 

 the (ield. The author's experiments have been continued since 1894, and consist 

 in placing dough infected with cultures of an organism which he ol)tained from sus- 

 liks in the runways of mice about barns and in haymows. In all the experiments 

 dead mice were found in considerable numbers within a few days after the exposure 

 of the infected dough, and the mice continued to die rapidly for a period of about 

 1 week. 



In the case of 4 haymows which were infected in the manner just described and 

 thoroughly examined 10 days after infection, the extent of mortality was found to 

 vary from 79 to 95 per cent. The species of mice chiefly concerned were Mus (James- 

 ticKxaui] M. mnsciclus. The author believes that this method is practical and exceed- 

 ingly effective under such conditions. 



Studies on the economic importance of insectivorous birds, G. EoRiCi 

 {Arb. K. Gesundheitsamte, Biol. Abt., 4 {1903), No. 1, pjo. 1-50, figs. ^).— The author 

 discusses in.all its bearings the general problem of the economic relations of birds. 

 In order to obtain a clear conception of the value of birds, it is considered necessary 

 to determine what insects are beneficial and to what extent; the quantity of food, 

 especially injurious insects, consumed by insectivorous birds; and the species of 

 insects which serve chiefly as the food of these lairds. The author discusses in great 

 detail the question of what insects may be considered beneficial, and concludes 

 that the value of parasitic and predaceous insects to the farmer has been greatly 

 overestimated. 



The agency of insects in fertilizing flowers is noted and conclusions reached that 

 insects are of more benefit in this regard than in any other. While about 3,000 

 species are known as constant visitors of flowers, the number which are really of 

 importance in the pollination of flowers is much smaller. The most important 

 families are bees, wasps, Muscidee, Bombylida?, and Syrphidte. None of these 

 species, however, possess a power of flight which would insure them against the 

 attacks of insectivorous birds, but as a rule the beneficial insects appear to be fully 

 as well if not better protected from destruction by birds than are injurious species. 

 The author states emphatically his belief, based upon numerous experiments and 

 personal observations, that parasitic and predaceous insects can not be depended 

 upon to control any injurious species, or even greatly to reduce its numbers. 



In order to determine the amount and kind of food of insectivorous birds the 

 author carried on a number of feeding experiments in large aviaries in gardens. 

 The birds employed in these experiments included a number of species fed various 

 kinds of food, including beneficial and injurious insects. The behavior of the dif- 

 ferent species and their economic value are discussed in detail. The author con- 

 cludes from these experhnents that the destruction of insects by insectivorous birds 

 may be so extensive as to greatly reduce the numbers of injurious species in any 

 locality. The author's experiments in determining the preferred food of various 

 insectivorous birds are presented in detail and indicate the importance of continuing 

 experimental work in this line, and also support the author's conclusion regarding 

 the value of insectivorous birds. 



The relation of insectivorous birds to fruit growing, J. P. Fort {Proc. Georgia 

 State Hart. Soc, ;>7 {1903), j)p. 70-75) .—Attention is called to the insectivorous habits 

 of a large number of common birds, and to the value of these birds to the farmer. 



