BIOLOGY. 301 



or ponds. A pond near Trenton was stocked with them in 1857, 

 and is now full of specimens, weighing sometimes 5 pounds. 

 They have become so different in color from the same fish as found 

 in the Delaware and on the coast, that Dr. Abbott at first thought 

 them quite distinct ; and he says they have changed considerably, 

 but only in color, during the last 10 years. 



PHYSIOLOGY OF FATS. 



The new number of the " Zeitschrift fur Biologie" (vi. i.) 

 contains an interesting paper by Subbotin "On the Physiology 

 of Fats." Towards an answer to the question, Is there in the ani- 

 mal organism any direct passage of fat from the alimentary canal 

 to the cells of adipose tissue ? a lean dog was fed for a month 

 on meat, spermaceti, and common fat. Of the 1,000 grms. of 

 spermaceti swallowed, 800, at least, were absorbed ; but the 

 merest trace only of spermaceti could be found in the fatty tissue 

 of the body at the close of the experiment. Spermaceti, therefore, 

 though absorbed and consumed in the economy, is not stored up 

 unchanged. Hence there is a presumption that the same is the 

 case with other fats (though it is obvious that many possible 

 events might negative the presumption). Towards solving the 

 further question, Are fats formed in the body out of proteids? a 

 dog reduced to the utmost leanness was fed on leanest meat and 

 palm oil (palmitin and olein), for 25 days, during which he gained 

 3 kilos in weight. The fat of the body was, at the close, found 

 to contain 13.9 per cent, of stearin. Though none had been 

 taken, a very considerable quantity of stearin had therefore been 

 formed in the body. A very lean dog was fed for 6 weeks on lean- 

 est meat, and a soda soap made with palmitic and stearic acids 

 only. At the end of the experiment, the dog having gained over 

 3 kilos in weight, the fat of the body was found to consist of 53.6 

 per cent, palmitin, 13.4 per cent, stearin, and 33 per cent, olein. 

 A large quantity of olein had therefore been formed in this case. 

 But if olein was thus formed, possibly the palmitin and stearin 

 were likewise formed from proteids, and not by synthesis of the 

 fatty acids with the glycerine of the economy. Subbotin further 

 points out that olein is more abundant in the subcutaneous than 

 in the deep-seated fat; possibly on account of a less energetic 

 transformation of proteids in the cooler surface regions ; so also in 

 cold-blooded animals the fat is proportionally richer in olein. 

 Nature. 



AGUE POISON. 



M. P. Bolestra has communicated to the French Academy some 

 observations on ague poison. He says, that in examining marsh 

 water he always finds, in proportion to its degree of putrefaction, 

 a granular microphyte, somewhat resembling in form the Cactus 

 Peruvianus. It is always accompanied by a considerable quantity 

 of small spores, one-thousandth of a millimeter in diameter, green- 



