214 



SCIENCE 



[N. S. Vol. XL. No. 1023 



Blood smears of a native rat, probably a 

 species of Euneomys, caugbt at Verrugas 

 Canyon, have shown nothing definite. Smears 

 of the blood of dogs and burros, doves and 

 ground-ov?ls from the same locality have like- 

 wise proved negative. The vizcachas, Yiscac- 

 cia spp., are contraindicated as a reservoir of 

 verruga. It has not yet been practicable to se- 

 cure vizcacha blood smears from the verruga 

 zone, but these animals do not occur close to 

 the house in Verrugas Canyon, where the 

 Plebotomus is very abundant in the rock walls, 

 which it evidently leaves only to enter the 

 house or attack persons and animals close by. 

 Therefore these particular gnats are precluded 

 from deriving their infection from the vizca- 

 cha, and they are well known to be infected at 

 most times if not continuously. 



In conclusion it may be pointed out that, on 

 a priori grounds, the inference is logical that 

 the lizards constitute a verruga reservoir. 

 The Phlehotomus passes the daylight hours 

 within the darkened recesses of the loose stone 

 walls and piles of rock in order to escape wind 

 and strong light. Lizards inhabit the same 

 places, finding their food there and coming out 

 only briefly at rare intervals to sun them- 

 selves. The Phlehotomus is always ready to 

 suck blood in the absence of light and wind, 

 and has been found more prone to suck rep- 

 tilian than mammalian blood. Nothing is more 

 natural than that the Phlehotomus should 

 suck the blood of the lizards to a large extent 

 during the day, and this is what actually 

 happens. If the Phlehotomus carries verruga, 

 and this is already demonstrated to be the fact, 

 it follows that the lizards must become in- 

 fected therefrom even if they were not orig- 

 inally so. That they are probably the original 

 reservoir of the disease is indicated in general 

 by the constant host relation which obtains 

 between Phlehotomus and reptiles the world 

 over and specifically by the mutual habitat of 

 the two which has resulted in their being 

 thrown continually together since their exist- 

 ence began. 



Chaeles H. T. Townsend 



Chosica, Peru, 

 April 27, 1914 



SPECIAL ASTICLES 



ON THE ANTAGONISTIC ACTION OF SALTS AND 



ANESTHETICS IN INCEEASING PERMEABILITY 



OP FISH EGGS (PRELIMINAKT NOTe) 



In previous papers^ it was shown that pure 

 salt solutions and nicotine increased the per- 

 meability of fish eggs and that these permeable 

 eggs developed abnormally, giving rise to cy- 

 clopia and other abnormalities common to fish 

 embryos. During the present season I have 

 observed a few cyclopic or one-eyed pike em- 

 bryos in the hatching jars of the State Fish 

 Hatchery, St. Paul, Minnesota. Eggs of the 

 pike and muskalonge were found to live in 

 water re-distilled in quartz and to be adaptable 

 to permeability experiments. Pike eggs were 

 used, and although they were not as imperme- 

 able as Fundulus eggs, they were normally 

 but very slightly permeable to salts. They 

 were placed in distilled water and in solutions 

 of anesthetics or of sodium nitrate, and the 

 chlorides diffusing out of them estimated 

 quantitatively with the nephelometer. Ex- 

 cept for the use of the nephelometer, which 

 admitted of a quantitative estimation of very 

 minute quantities of chlorides, the technique 

 was the same as given in the previous papers. 

 If one or more eggs died in an experiment, it 

 was repeated. Pike eggs will live in 3 per 

 cent, alcohol for many days and in 6 per cent, 

 alcohol for a considerable length of time. 



Six per cent, alcohol, or i saturated (more 

 than 1 per cent.) ether, or t^ molecular sodium 

 nitrate increased the permeability of the eggs. 

 This change was irreversible, but did not kill 

 the eggs — after the eggs were put back into 

 distilled water they remained permeable. 



When a salt and an anesthetic were com- 

 bined in the same solution, it was found that 

 the anesthetic antagonized the action of the 

 salt. This antagonism was not very marked, 

 but seemed to be constant. The method of 

 procedure is shown by the following example : 

 A mass of pike eggs was divided into three 

 exactly equal lots. Lot 1 was placed in 50 c.e. 

 iu molecular NalSTOj. Lot 2 in 50 c.c. A mo- 

 lecular ISTaNOj containing 3 per cent, alcohol. 



iMcClendon, Science, N. S., Vol. 38, p. 280; 

 and Internat. Zeitsch. f. FhysiTc.-Chem. Biologie, 

 1914, Vol. 1, p. 28. 



