I have given my reasons before (_Ants and Spiders_, p. 127) for believing that the trap-door spiders do not as a rule desert their nests, but enlarge them from time to time to meet their own requirements of growth; showing, by a comparison of the measurements of the doors of eight nests in April with those of the same nests in the following October, that all had increased in size. Subsequent observations have confirmed this; I find that the young spiders taken from the mother's nest enlarge their nests in captivity in a precisely similar way. Thus, for example, the wafer doors of three young _Eleanora_ spiders, made within a few days after their removal from the mother's nest on February 20th, 1873, and first measured on February 28th, had increased between that date and Nov. 29th following from 2 to 4 lines, 2-1/2 to 4 lines, and 2-1/2 to 6 lines respectively. It is unfortunate that the male and female spiders are undistinguishable when very young, as it would be interesting to know whether the males construct nests before they take to their adult life, during which they roam from place to place and hide under stones. In one case fourteen young spiders, forming this entire family taken with a female _N. Manderstjernæ_, made nests; so that unless all of these were females, we have evidence here to prove that the males do commence life by building nests for themselves. I kept the male _Cteniza Moggridgii_, for ten days on damp earth in captivity, but he made no attempt to excavate or spin, and wandered restlessly about, scarcely touching the flies[152] with which I supplied him. [Footnote 152: I habitually fed my captive spiders with common house-flies, and it was curious to see how entirely the latter were wanting in any instinctive fear of even the largest spiders. They would creep between the spiders' legs, causing them to start as if electrified, and frequently it was not until the flies, after repeating this annoyance several times, actually walked up to and almost touched the fangs of the spider, that they were punished for their ignorance and presumption.] Seeing this I could not venture to prolong his captivity, as I feared to risk injuring a specimen which was quite unique and which there was little likelihood of my being able to replace. It is rather curious that M. Simon should also have found one male, and one only, of the closely-related _Ct. fodiens_ of Corsica, and that his specimen should be, like mine, the only one known. Bearing in mind the curious problems which arise as to the affinities of the flora and fauna of the Alpes Maritimes with that of Corsica, the fact that the species of _Cteniza_ which is found at Mentone, though allied to, is yet distinct from the insular species, gains a new interest.