Observations of this kind are difficult to make satisfactorily, at least in the case of the trap-door spiders with which I am acquainted, and which appear to be nocturnal in their habits. I have certainly never seen them out of their nests in the daytime, and but rarely detected one of them (Nemesia cæmentaria) even venturing to peer out of her door set ajar for the purpose.[74]
[74] M. Olivier, however, states (Encyclopédie Méthodique, tom xviii., p. 228, Art. Araignées Mineuses, Paris, 1811) that he has twice found nests in the islands off Hyères and on the promontory of St. Tropez the doors of which were set open in the daytime and the tube empty, this seeming to imply that the spiders were out hunting and were diurnal in their habits. He did not see the spiders, but from his description the nest was of the cork type.... Here is an interesting point, and one which those naturalists who make Hyères the field of their observations should endeavour to throw further light upon.
The following very singular account is given by M. Erber[75] of the habits of Cteniza ariana, which he watched in the island of Tinos. I quote from the abstract given in the Zoological Record cited below:—"At night these spiders come out of their nests, fasten the open trap-door to neighbouring objects, and spin a net, about six inches long by scarcely half an inch in height. In the morning the nets were removed, and Erber believes that the net of each night is added to the trap-door. He found eggs at the bottom of the tubes, attached singly to threads, to the number of about sixty. The young seem to form dwellings very early."
[75] In Verhandlungen der k. k. zool. bot. Gesellschaft in Wien, vol. xviii. pp. 905, 906, quoted in Zoological Record, vol. v. p. 175 (1868); see also [Appendix B].
It would be very interesting to know whether these nocturnal habits are also found in our spiders on the Riviera.
I have been favoured[76] with a sight of an unpublished manuscript by Mr. Hansard giving an account of his observations on Cteniza fodiens, made in Corfu. This gentleman states that some of these spiders which he kept in captivity, used to come out at night, and might sometimes be surprised roaming about the room at a very early hour in the morning. He, however, relates that he had received from a friend an account of a trap-door spider inhabiting the island of Formosa, in the China seas, which constructed nests similar to those of Cteniza fodiens, but which were habitually to be seen outside their nests in the daytime, attracting attention by "staring at" any one who might approach, and then hurrying back to their nests and closing their doors after them.
[76] I am indebted to Mr. Moseley for procuring this MS., and to Prof. Rolleston, whose property it is, for permission to make use of it.
Lady Parker has also told me of some black trap-door spiders which were so common about Paramatta, near Sydney, in Australia, that scarcely any one paid attention to them, and which might habitually be seen out on the garden paths in the daytime near their holes, to which they would run in all haste when alarmed. The eye of the passer-by was attracted by the open doors, which were about the size of a sixpence, and fall over backwards when the spider makes her exit, but when closed, on her return, they fit so neatly that it is extremely difficult to detect them.