ON NOCTURNAL ANIMALS. 317 
and procurable for examination. Except in damp weather and 
dull days, they are shy and not much given to be abroad; but in 
the evenings, all through the night and early morn, especially 
during moist weather, they crawl hither and thither with 
unrestrained freedom. Keen fishermen know when best to seek 
their bait, and the proverb of the “early bird finding the 
worm” points to grey dawn. Here then we see that the 
nocturnal habit of the one creature superinduces the necessity 
of similar habit in the other. The bird’s own enemy, again,— 
it may be reptile or mammal,—nust stir betimes; and thus, from 
class to class, the nocturnal and crepuscular habit is transmitted. 
Once acquired and perpetuated, modification of organs adapted 
to the altered circumstances ensues. Tactile sensation among 
groups of the Vermes is through minute skin modification, 
papille, bristles, or cup-shaped bodies, all in connection with the 
nervous system. Though the earthworm itself is blind, it is not 
so with others, where evolution of visual organs from indifferent 
condition to complex lens, crystalline rods, cones, &c., is well 
marked. Auditory organs are also present in some. 
With regard to the Mollusca, and with them we may associate 
the Crustacea, some doubtless are nocturnal; others live at depths 
where only a modicum of light is admissible. Not a few 
retreat to darkness under cover of rocks, stones and sea-weed. 
But slugs and snails are active after sundown, and all night 
long commit their ravages, while their reptilian and avine 
pursuers have to follow suit. 
Of Arachnida, Myriapods, and quite a host of the division of 
Insecta, one is at a loss by the embarras de riches of those that 
earry on their life occupations under cover of darkness. Suffice 
to recall some of the Trap-door Spiders and their ingenious 
devices so graphically pourtrayed by Mr. Moggridge; while to 
those who have felt the effects of the nocturnal attack of the 
venomous Scorpion, the name is sufficient. Deeply interesting is 
Mr. Moseley’s researches on the caterpillar-looking nocturnal 
Myriapod of the Cape of Good Hope (Peripatus capensis). It is 
there quite local in habitat, and is found under dead wood, where- 
from it creeps out at dusk. A pair of horn-like antenne project 
from its head, and it crawls by the aid of seventeen pairs of 
hooked, conical feet. It breathes air by trachea and stigmata. 
Cutaneous glands secrete a viscid fluid, which, Capt. Hutton 
