VENOMS IN THE ANIMAL SERIES 321 
loses its properties. By the ordinary methods of immunisation 
it 1s possible to obtain a very active antilysin. 
There is, therefore, a very close analogy between the venoms 
of toads and salamanders. These highly complex substances are 
composed of mixtures of poisons, some of which are in all 
respects analogous to the vegetable alkaloids, while others are 
closely related to the microbic toxins and snake-venoms. 
In the spawning season the cutaneous glands of the male toad 
are gorged with venom, while those of the female are empty. 
Phisalix* has shown that at this period the venom of the female 
is accumulated in the eggs, which, if extracted from the abdomen 
at the moment of oviposition and dried in vacuo, give off in 
chloroform a product that has all the toxic properties of cutaneous 
venom (bufotalin and bufotenin). No trace of this poison is to be 
found in the tadpoles. 
B.— Lizards. 
The Order LAcERTILIA includes only a single venomous species, 
which belongs to the family Lacertide, and is known as the 
Heloderm (Heloderma horridum, fig. 124). It is a kind of large 
lizard, with the head and body covered with small yellow tubercles 
on a chestnut-brown ground. It sometimes exceeds a metre in 
length, and its habitat is confined to the warm belt extending 
from the western slope of the Cordilleras of the Andes to the 
Pacific. It is met with especially in the vicinity of Tehuantepec, 
where it inspires the natives with very great dread. It is a slow- 
moving animal, and lives in dry places on the edges of woods. 
Its body exhales a strong, nauseous odour; when it is irritated, 
there escapes from its jaws a whitish, sticky slime, secreted by 
its highly developed salivary glands. Its food consists of small 
animals. Its bite is popularly supposed to be extremely noxious, 
but, as a rule, the wound, though painful at first, heals rapidly. 
' Comptes rendus de l'Académie des Sciences, December 14, 1903. 
21 
