XIV POISON——PERDIEIDY 365 
species regarded as especially venomous must be mentioned 
Phidippus morsitans, one of the larger of the Attidae. 
It is exceedingly likely that the bite of the large tropical 
Aviculariidae is really formidable. They appear, however, more 
anxious to escape than to show fight, and we possess httle reliable 
information with regard to them. Doleschall shut up small 
birds with two West Indian species, and death followed their 
bite almost immediately. Ten days’ starvation appeared to 
weaken the venom, for a bird bitten by a spider fasting for that 
period recovered after an indisposition of six hours. 
Most Arachnologists have recorded experiments with regard to 
the venom of the commoner European species, with equally con- 
flicting results. Blackwall came to the conclusion that loss of 
blood, and not poison, caused the death of spider-bitten insects. 
He could not himself distinguish a spider bite from the prick of 
a needle inflicted upon his hand at the same time. Bees, wasps, 
and grasshoppers survived the bite about as long as other insects 
of the same species outlived a needle-prick in the same part of 
the body. Walckenaer’s experience was of the same nature. 
Bertkau, however, when bitten in the hand, felt clear indications 
of an irritant poison in the wound. The hairs of some of the 
large hairy species of the Aviculariidae possess poisonous 
properties. They are readily parted with, and when the animal 
is touched by the hand considerable irritation is set up. 
Fertility of Spiders.—Spiders vary greatly in the average 
number of eggs laid by different species, and within the limits of 
each species there is a very considerable variation in fertility. 
As a rule it appears that the large and vigorous spiders are more 
prolific than the smaller and weaker members of the order. 
Were all the facts before us, however, we should no doubt find 
that the number of eggs laid bore a direct proportion, not to the 
size of the species, but to the dangers to which the young of 
that species are exposed. Where the total numerical strength of 
a species is fairly stationary, such a proportion must of course 
exist. Some species, no doubt, are tending to become extinct, 
while others are increasing in numerical importance. As a 
general rule, however, it is safe to infer that, if a species 1s 
especially prolific, special dangers attend the rearing of the young. 
The largest of North American Epeirids, Argiope cophinaria,' 
1 M‘Cook, American Spiders and their Spinning Work, ii., 1890, p. 188. 
