Feb. '08] JOURNAL OF ECONOMIC ENTOMOLOGY 51 



sand; water poured into this will gradually percolate through and 

 moisten the sand. 



For longevity experiments ticks are best kept in this way, observa- 

 tions being' readily made through the glass without disturbing the 

 ticks. These tubes may be kept outside inserted in the soil and the 

 longevity of the stages determined under the prevailing or normal 

 climatical conditions which, however, are not always the most favor- 

 able to longevity. In determining the longevity of ticks on grass and 

 weeds, a screen cage is necessary to assure protection from accidental 

 intrusion. 



The life history of the Spinose Ear Tick, Ornithodoros megnini, has 

 been determined by attaching to the ears of animals bags held in 

 place and prevented from being rubbed off by tying to a cord about 

 the horns. 



SOME LIFE HISTORY NOTES ON THE SOUTHERN 

 CATTLE TICK 



(Illustrated with Lantern Slides.) 

 By E. C. CoTTo::^, Enoxville, Tenn. 



(Withdrawn for publication elsewhere.) 



A TENTATIVE LAW RELATING TO THE INCUBATION 

 OF THE EGGS OF MARGAROPUS ANNULATUS 



By W. D. HuNTKR, Bureau of Entomology, U. S. Department of Agriculture. 

 Studies of the effects of temperatures upon insects have always 

 held great interest and have frequently led to results of practical 

 value. In this country the principal work has been done by Dr. L. 0. 

 Howard, who in 1896 in a paper read before this Association, ''Some 

 Temperature Effects on Household Insects,"^ pointed out exactly 

 how cold storage practice could be utilized in the control of certain 

 species. A year before, the same entomologist had shown the proba- 

 bilities of the restriction of imported injurious species to certain life 

 zones which, of course, are predetermined by temperatures.'' Later 

 Doctor Howard in his paper on the geographical distribution of the 

 yellow fever mosquito made much the most interesting and important 

 contribution to the subject.'' He showed how the range of Stegomyia 

 calopus was determined by temperature and how the exact limitations 

 of the regions in which this mosquito, if accidentally introduced, 

 might be expected to become perfectly established, could be deter- 

 mined by computing the accumulated effective temperature. 



aBul. Bur. Ent. 6, p. 13-17. bProc. Ent. Soc. Wash. 3: 219-226. 



cPublic Health Rep'ts, 18, No. 46. 



