General Meeting-April 23-25, 1925 The Annual General Meeting of The American Philosophical Society will be held on April 23d, 24th, and 25th, 1925, beginning at 2 P. M. on Thursday, April 23d. Members are requested to send to the Secretaries, at as early a date as practicable and before March 18, 1925, the titles of papers which they intend to present so that they may be announced in the preliminary programme which will be issued immediately after that date and which will give in detail the arrangements for the Meeting. It is understood that papers offered are original contributions which have not been theretofore presented. All papers presented which are favorably acted on by the Publication Committee will, in accordance with the rules of the Society, be published as soon as practicable in either the Proceedings or the Transactions as may seem best. ARTHUR W. GOODSPEED Secretaries Members who have not as yet sent their photographs to the Society will confer a favor by so doing; cabinet size preferred. It is requested that all correspondence be addressed TO THE SECRETARIES OF THE AMERICAN PHILOSOPHICAL SOCIETY 104 SOUTH FIFTH STREET PHILADELPHIA, U. S. A. WENRICH, D. H. 1916. The Spermatogenesis of Phrynotettix magnus, with Special Reference to Synapsis and the Individuality of the Chromosomes. Bull. Mus. Comp. Zoöl. Harvard, 59: 55–133. Pls. 1-10. v. WETTSTEIN, F. 1923. Kreuzungsversuche mit multiploiden Moosrassen. Biol. Zentralbl., 43: 71-83. 1 text fig. WILSON, E. B. 1912. Studies on Chromosomes VIII. Jour. Exp. Zoöl., 13: 345-448. Pls. 1-9. YELLOW FEVER AND FISHES IN COLOMBIA,1 By C. H. EIGENMANN. Read April 25th, 1924. Dr. H. Hanson, of the Rockefeller Foundation, who two years ago fought yellow fever in Peru, has transferred his operations against yellow fever to Colombia. He has kindly sent me a series of the fishes he has found useful or is trying out. Comparing the species received from Colombia with those used by him in Peru and those used by Drs. Pareja and Connor in Ecuador, some general conclusions may be pointed out. The two essentials to make a fish useful for yellow fever work are: (1) The inclination to eat mosquito larvæ. (2) The ability to exist in the containers in which yellow fever mosquitoes breed. No doubt scores of species fulfill these two requirements in different parts of the fever-infested or potential fever region. Which ones are best in a given area will have to be worked out experimentally. This much seems clear. Other things equal, small species of fishes will be more suitable than large species, though the young of some large species may answer the purpose very well. Other things being the same, species living in ponds, or stagnant water, are more likely to be serviceable than those from swift water. Some species pick up their food by sight. Other things equal, they may be quite effective in removing moving mosquito larvæ during daylight. Other species detect their food by its motion. Such species are usually provided with elaborate tactile organs either in the skin itself, like the blind-fishes, or in barbels like various catfishes. These may also be useful, frequently operating at night. It will probably be found that many of the fishes imported by aquarists will be suitable for mosquito work in the tropics. 1 Contribution from the Zoölogical Laboratory, Indiana University, No. 202. The most effective mosquito larvæ eradicator in Peru is "Life," Pygidium piuræ. In Colombia, near Bucaramanga, a smaller species of the same genus is being used, Pygidium striatum. Every mountain brook in Colombia contains one or more species of Pygidium, if they are really all distinct. They sometimes are found under rocks in swiftly flowing water. I found one species in a little brook near Honda diving into the sand and small gravel at the bottom. When disturbed or routed out of one spot, they quickly darted into another. In the uplands they have a tendency to live in quieter water. They have barbels and the Peruvian P. piuræ operates at night. The "Volador" (Piabucina panamensis) used in Colombia is a close relative of one of the most effective mosquito eradicators used in Lima, Peru, under the name of Liza de agua dulce, in Ecuador as Huaijas" and at Chiclayo, Peru, as "Chalquoque." The name "Volador" suggests the reputation of "Chalquoque" which has a tendency to jump out of its containers. This habit no doubt contributed to its distribution. It has recently been taken in a line entirely across the Andes from Pacasmayo to Cajamarca and down to the Marañon, and is the only species of fish with such an extravagant distribution. The "Mero" is being used at Barranquilla. We became acquainted with its next door relative in the yellow fever work at Guayaquil under the name "Chalacos." The Pacific slope form is Dormitator latifrons, that in Barranquilla and along Atlantic slope fishes generally is Dormitator maculatus. The Pacific slope form proved very effective and there is every reason to believe that the Atlantic slope form will prove equally so, if it is found in sufficient abundance. 3 The three species of fishes used most effectively in Peru and Ecuador have counterparts, close relatives systematically, which are doing the work in Colombia. Another species being used in Colombia is a "Mojarra.” The Mojarras are sunfish-like fishes. There are several genera and species. Dr. Hanson experimented with Equidens rivulatus in Peru. 2 See Am. Nat., LVII., pp. 446 and 447, for figures and distribution map. 3 See Proc. Am. Philos. Soc., LXI., p. 204, 1922. |