1 88 



NATURAL SCIENCE. 



to the nature of the secretion of toads and salamanders. Gratiolet 

 and Cloez at first (13) regarded it as an acid, but in a later paper (14) 

 pronounced it to be an alkaloid, which view was also held by Zalesky 

 (28). Quite recently, Phisalix (21) claims to have solved the question 

 by reconciling both views : toads and salamanders are simultaneously 

 possessed of two different kinds of glands, different both anatomi- 

 cally and physiologically. These are mucous or slime glands, spread 

 over the greater part of the body, the exudation of which is controlled 

 by the animal ; and specific glands (the parotoids and the larger 

 dorsal glands), the product of which can only be squirted out by 

 foreign agency. The secretion of the former glands is an alkaloid, and 

 acts as a narcotic ; that of the latter is an acid, and acts as a convul- 

 sive. The anatomical differences of the two kinds of glands have 

 been worked out by Paul Schultz (25), who, however, regards the 

 product of the slime-glands as innocuous. 



The frogs, so sensitive to the poison of other Batrachians, are, 

 nevertheless, not free from toxic properties. This fact, first noticed 



.j.j^^ei^M'' 



Fir.. 2.—DeiuUohatn liuctoriiis {Pli_\llvbiilt-s clwcneiisis, Posada-Arango). 



by Vulpian (27), has been placed beyond doubt by the experiments of 

 Paul Bert (3). A goldfinch inoculated with the secretion of the 

 edible frog died in one minute, a frog of the same species in one hour 

 and a quarter. 



We still know very little with regard to the poisonous secretions 

 of exotic Batrachians. Lacerda Filho (10) has experimented upon 

 the common toad of Brazil, and Posada-Arango (23) informs us that 

 the Indians of Colombia employ the secretion of a small frog, Dendro- 

 hates tinctoriits {rena.medPJiyllobates chocoensis by thsit author), for poisoning 

 their arrows. The exudation is obtained by exposing the frog to a 

 fire, and after being scraped off the back is sufficient for poisoning 

 fifty arrows. Posada-Arango's experiments on small mammals and 

 birds have shown the poison, which he calls Batracine, to act on the 

 central nervous system, like that of the Salamander, the Samandarin 

 of Zalesky, or Salamandrinc of French authors, not on Jhe heart like 

 toad-poison, for which he uses the name of Bujine. The name 



