Jan. 1, 1S6S.] 



HARDWICKE'S SCIENCE-GOSSIP. 



15 



This line she fastens to one of those which proceed 

 from the mouth of her nest, which just serves to 

 suspend the object. Returning, another thread is 

 attached to it, and it is suspended midway between 

 the earth and nest. A third trip serves to fix the 

 substance at the mouth of her domicile, to be after- 

 wards more neatly arranged. Several objects are 

 thus frequently suspended, giving the nest at times 

 a rather unfinished appearance, as represented in 

 the foregoing figures. 



Owing to the abundance of suitable materials to 

 be obtained, those nests constructed in the open air 

 are almost impervious to light, whilst those built by 

 the spider when kept in confinement admit the 

 light through the various interstices left by angular 

 pieces of wood, &c. The little creature seems unable 

 to remedy this, the objects being invariably attached 

 by the inner surfaces only, and I have scarcely ever 

 observed one of the busy little workwomen on the 

 exterior of her house, excepting when forming a 

 slight covering of silk on the upper part, which is 

 sometimes done. 



The snare consists of a few threads, apparently 

 disposed without any order or arrangement : this, 

 however, is not the case. Prom the mouth of the 

 tube lines proceed to surrounding objects. The 

 disposition of these threads is such that they enclose 

 an inverted funnel-shaped space ; the mouth of the 

 nest representing the point of the funnel; thus 

 affording the spider who takes her station at the 

 entrance a convenient point for observation, &c. 

 Several of the threads serve to steady the fragile 

 dwelling; others, being thickly covered with the 

 viscid globules, ensnare the unwary insect. Occasional 

 deviations from this form may be observed, but as a 

 rule, the outlines represent the figure described. 

 Nests in course of construction are represented by 

 figs. and 7. 



These are the forms commonly met with in newly- 

 built nests ; they however assume a more conical 

 form as they are enlarged, owing, no doubt, to the 

 increased weight of materials used and the slight 

 way in which these materials are attached together. 



From some unknown cause, the creatures kept by 

 me have sometimes left their homes with their 

 broods, and have built on the under side of a branch 

 irregular structures : one is figured above (fig. 8). 



The nests themselves form pretty objects, whilst 

 the few hours spent in watching my tiny friends 

 will afford the lover of nature much gratification; for, 

 believe me, it is productive of much pleasure and 

 instruction to study the habits of even a spider. In 

 the economy of nature, spiders perform the same 

 important office as regards insects that the carnivora 

 do with respect to the herbivora — viz., prevent their 

 too rapid multiplication; and although the foolish 

 and ignorant may deem them cruel and ferocious, 

 they but obey a law of their nature implanted by 

 the All-wise Creator, whose beneficence is as 



manifest in the care with which He has provided 

 for the humblest and most despised creatures, as 

 in the abundant provision which He has made for 

 beings more immediately useful to man. — Edward 

 II. Robertson, Brixton. 



LONDON COCKROACHES. 



{Ectohius germanica.) 



PT1HE two species of Cockroaches commonly found 

 -*- in London houses are both importations from 

 abroad. One, the Blatta orientalis, or ordinary 

 " black-beetle," whicli swarms in .every locality, 

 comes from the East Indies ; the other, a North 

 American insect, the Blatta Americana, is larger 

 than the first, and of a light reddish brown colour. 

 We read of this species that " it is met with oc- 

 casionally in warehouses and outbuildings by the 

 Thames, especially below London Bridge." Of 

 late years, however, the Blatta americana has 

 extended entirely across the metropolis, as it is 

 found in Red Lion and Bloomsbury Squares, and in 

 the Zoological Gardens, Regent's Park. 



Fig. 9. JZctobius Germanica. 



Two other species of Cockroaches are known in 

 London — the Blatta maderae, a native of Madeira 

 and the adjoining islands, has been frequently taken 

 in London ; and the enormous Blatta gigas, from 

 Western India, is common in our West India 

 Docks. This objectionable insect is called the 

 "Drummer" — the noise it makes keeping people 

 awake all night. 



These four species, all of them foreigners, belong 

 to the genus Blatta; but the British species of 

 Cockroach have been very properly separated from 

 Blatta by Mr. Westwood, and formed into the 

 genus Ectohius. About a dozen species are supposed 

 to be indigenous to this country. They are smaller 

 than the species of Blatta ; and whereas in Blatta 

 the first joint of the tarsus is longer than the others 

 taken together, in Ectohius it is scarcely so long. 

 In Blatta, also, the males possess two styles within 

 the two jointed organs projecting from the abdomen; 

 and the females are wingless ; while in Ectohius 

 these styles are wanting, and the wings are common 

 to both sexes. 



