Geology and Natural History. 75 



Most of the new forms and all the new species are compound 

 ascidians, which are nn usually numerous at the Bermudas. Most 

 of these were studied from living specimens, as well as from large 

 series preserved in different media. Nearly all the species are 

 illustrated by anatomical drawings, and most of the new ones by 

 reproductions of photographs, showing the general appearance. 

 Some of the photographs were made jroni living specimens, under 

 water. It is altogether the most important work hitherto pub- 

 lished on the ascidians belono-ino- to the West Indian fauna! area. 



A. E. T. 



13. The Embryology of « Brachiopod (TerebratuUna septen- 

 trionalis) ; by E. G. Conklix. Proc. Amer. Phil. Soc, xli, No. 

 168, pp. 41-76. 10 plates. 1902. — This i^, in many respects, one 

 of the most complete accounts of the early stages of a Brachiopod 

 that has been published. The author adds a discussion of the 

 zoological affinities of the Brachiopods, concluding that from 

 embryological data they are nearest to Pharonis and the Polyzoa. 



A. E. V. 



14. Results obtained in Sacana from the destruction of the 

 Stegomyia fasciata infected by Yelloic Fever; II. The Propa- 

 gation of Yelloio Fever ; by Major W. A. Gakgas, Medical 

 Corps, U. S. Army. Sanitary Dep., Havana, Ser. 4, 1902. — These 

 two papers are of great interest and importance as demonstrating 

 that yellow fever in Havana is transmitted by this particular 

 mosquito, and in no other way. The disease was fully controlled 

 simply by destroying these mosquitoes in various ways, and pre- 

 venting them from gaining access to fewer patients, by the liberal 

 use of screens. By these means, and without special disinfection 

 of rooms or clothing, the fever was reduced to a minimum after 

 March, 1901, when this method was commenced. No cases what- 

 ever occurred during the four months from October to January 

 inclusive, which has not happened before in 150 years or more. 

 The average number of deaths from yellow fever from April 1st 

 to December 1st, since 1889, had been 410.54, but by the anti- 

 mosquito methods it was reduced to 5, in 1901. Yet in 1900, with 

 the most careful and elaborate methods of ordinary disinfection, 

 very little impression was made on the yellow fever, for there 

 were 1244 cases and 310 deaths in 1900, but in 1901 there were 

 only 18 deaths, 12 of which occurred in January and February, 

 before the destruction of the mosquitoes was commenced. Yet 

 the conditions were in other respects very favorable for a bad epi- 

 demic in 1901, for about 40,000 non-immune emigrants had 

 arrived, — a larger number than ever before. In view of such 

 results there seems to be no doubt whatever that the true source 

 of the yellow fever infection has been demonstrated and also 

 that the disease can be easily and surely controlled in all cases, if 

 suitable care be used to destroy this pernicious mosquito. More- 

 over, the same efforts will simultaneously eradicate the malarial 

 fevers. a. e. v. 



