MAMMALIA 



279 



Heloderma suspeetum Cope, 1869. 



Cope gave the lizard the name suspeetum, because he suspected that its 

 bite would be found to be poisonous. This lizard is found in the United 

 States — in Arizona, Texas, Utah, New Mexico, and Southern California — 

 where it is called the ' gila monster.' The poison apparatus consists of 

 glands under the lower jaw and teeth in that jaw. 



The poison gland in this species lies on either side of the lower jaw, and 

 from its mesial aspect four ducts pass upwards, each towards its opening on 

 the outer surface of the mandible, through which it passes obliquely upwards 

 and inwards, to end at the base of a tooth near the termination of a groove. 



The upper teeth are also grooved, but Schufeldt failed to find any gland 

 wherewith they could be supplied with poison. 



There appears to be no doubt as to the poisonous nature of the secretion 

 from the glands above mentioned, for Bonberger records that a bite in the 

 leg of a guinea-pig caused convulsions and death in three minutes. 



Venom. — The venom was obtained by Mitchell and Reichert by making 

 the lizard bite a saucer. It was found to be alkaline, with a weak smell, and 

 to kill frogs, pigeons, and rabbits. 



The effects of gila poison have been most carefully investigated by Weir 

 Mitchell and Reichert, and by Van Denburgh and Wight. 



The latter consider that it differs in no important respect from snake- 

 venoms, causing death by acting rapidly upon the respiratory centre in the 

 medulla, and causing paralysis of respiration. Its other actions are to first 

 stimulate and then paralyze the heart by poisoning its muscular fibres. 

 On inoculation, there is an immediate great fall of blood-pressure, but whether 

 this is due to action on the vasomotor centre or not is not clearly known. 

 There is a secondary gradual fall due to cardiac failure. The motor nerves 

 and cells are not affected, but the sensory apparatus is at first rendered more 

 irritable and then paralyzed. Coagulation of the blood is at first accelerated 

 and then retarded, so that it may become incoagulable. Haemolysis may 

 occur. Local signs are almost nil, as a rule a little oedema and slight extrava- 

 sation being present. 



Symptoms. — Very severe pains radiating from the part, rapid swelling, 

 faintness, profuse perspiration, may be noted. 



Treatment. — A proximal ligature should be applied if on a limb, and per- 

 manganate of potash, 1-3 in 100, should be used to bathe the wound, which, 

 finally, should be dressed aseptically. 



FAMILY LANTHANOTID^ Steindachner, 1877. 



This family was formed for Lanthanotus Steindachner, 1877, which is the 

 type genus. It is closely related to Helodermidae. 



Lanthanotus borneensis Steindachner, 1877. 

 This lizard, which is closely allied to Heloderma, is suspected of being 

 poisonous, but there are as yet no proofs of this, especially as the teeth are 

 not grooved, and there is doubt as to the presence of poison glands. Its 

 habitat is Borneo, but it requires reinvestigation, as but few specimens are 

 known. 



MAMMALIA Linnaeus. 



The mammal suspected of causing poisoning is Ornithorhynchus paradoxus, 

 belonging to the Monotremata . 



MONOTREMATA Bonaparte, 1837. 

 Ornithorhynchus paradoxus Blumenbach. 1800. 

 As is well known, the males of this animal, which is only found in Australia, 

 have large spurs projecting backwards from their hind-limbs. These spurs are 

 hollow, and into them open the ducts of poison glands. The venom is an 

 albuminous fluid containing albumoses. 



