The Zoologist— June, 1809. 1713 



the wound in his hand into the blood : he was soon after seized with 

 vertigo, vomitings and faintings, and was carried to the house of his 

 parents, who called in a doctor immediately ; but already the malady 

 had made such progress, that in spite of the most energetic means 

 employed, the patient soon died." These experiments are recorded 

 in an English dress in the ' Zoologist' for 1852, at p. 3658, or in 

 Mr. Cooke's work on * Our British Reptiles,' p. 116 : they prove in a 

 most satisfactory manner that Metamorphotic Reptiles secrete a 

 virulent poison, and experience shows us that an instinctive knowledge 

 of its existence is protective to the animals themselves, since cats 

 almost invariably avoid contact with frogs, toads or newts, and dogs 

 absolutely refuse to attack them ; and if pertinaciously incited to 

 worry a frog or toad, a dog will be observed to froth at the mouth and 

 exhibit every symptom of abhorrence and disgust. In this there is 

 something very remarkable and worthy of admiration, for, of all 

 created beings, the Metamorphotic Reptiles are the most innocuous 

 and defenceless ; and were they not protected by the innate know- 

 ledge possessed by carnivorous animals of this poisonous property, 

 they must inevitably perish, and thus a useful race of insectivorous 

 animals would be utterly exterminated. Like most of the known 

 strong organic poisons, the active principle of toad venom is alkaline 

 in its character, almost insoluble in water, slightly soluble in ether, 

 and very soluble in alcohol. My correspondent, Professor Moquin 

 Tandon, in his ' Medical Zoology,' describes this secretion as "a thick 

 viscid milky fluid with a slight yellow tint and poisonous odour," — the 

 latter expression I do not fully appreciate, — and adds that " it has a 

 disagreeable caustic bitter taste : it becomes solid on exposure to air, 

 and assumes the form of scales when placed on glass." 



In the arrangement of memoranda, which have been many years in 

 the course of collection, it would have been satisfactory to have fol- 

 lowed some safe guide as to the classification of the species, but there 

 is none. Even so lately as in the January number of this periodical 

 it was shown that one of the principal orders in our artificial methods 

 is composed of the larvae of species belonging to a totally different 

 group (see Zool. S. S., p. 1569), a discovery which, while it destroys 

 our received conclusions, opens up a world of conjectures: it shows 

 us that such genera as Siredon, for instance, consist of larvae which 

 have the power of propagating their kind, and thus that an unascer- 

 tained number of generations may pass away before a single individual 



SECONP SEEIES — VOL. IV. 2 G 



