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THURSDAY, MARCH 28, iSgi. 



ORB-WEAVING SPIDERS OF THE 

 UNITED STATES. 



American Spiders and their Spinning Work ; a Natural 

 History of the Orb-weaving Spiders of the United States, 

 ivith Special Regard to their Industry and Habits. By 

 Henry C. McCook, D.D. Vol. iii., with descriptions 

 of orb-weaving species and plates (pp. 1-284, pi. i- 

 30). (Published by the Author, Academy of Natural 

 Sciences of Philadelphia, a.d. 1893.) 



VOLS. i. and ii. of this work have been already 

 noticed in these columns. (See Nature, vol. 

 xlii., p. 244, 1890; Ibid, xliii., p. 74, 1S90.) The 

 volume before us completes the work, and bears 

 date 1S93 ; but it was only issued to the public at 

 the end of 1894. To the general reader this is a 

 matter of little consequence, but to the specialist it is 

 often important, for it frequently happens, as in this 

 instance, that new genera and species are characterised 

 and described ; it then often becomes necessary to decide, 

 on the questions of priority that may rise, as exactly as 

 possible when such descriptions were made, and the date 

 inscribed on the work, it is manifest, cannot be implicitly 

 relied upon. 



In the preface to the present volume, it is stated that 

 the work has engaged the author's thoughts for more 

 than twenty y ars, and to this the amount of research 

 and observation testified to in three large volumes amply 

 bears witness. The first six chapters of vol. iii. (pp. i- 

 131), being part i., are a kind of supplement to vols. i. and 

 ii., and are "on various natural habits and physiological 

 problems'' of spiders. Part ii. (pp. 132-277) carries out 

 the prospectus of the work at first issued, viz. descrip- 

 tions of the American " orb-weavers," illustrated by 

 thirty coloured plates of great beauty and accuracy, 

 especially in regard to the anatomical details; two, how- 

 ever, of these plates are of spiders of various groups and 

 species alluded to in the foregoing part of the work, 

 though without special description. The author speaks 

 of this portion of his task (part ii.) as in many respects 

 its most difficult part ; but this may be taken as tolerably 

 certain, that though vols. i. and ii. and the first half of 

 vol. iii. will always be the most popular part, the latter 

 portion of vol. iii. will prove of most value to the scientific 

 world. The observation and detailing of habits, man- 

 ners, and general economy, whether of spiders or any 

 other group in the natural world, afford unlimited scope 

 for imagination, sentiment, as well as popular and 

 picturesque description, all of which the true scientific 

 worker has resolutely and wholly to shun, or, at any 

 rate, to repress with a strong hand. It seems almost a 

 pity that these two distinct portions of Dr. McCook's 

 work had not been issued separately, as the total cost 

 of the whole — 50 dollars — is a heavy sum to pay for 

 the 136 pages and thirty plates, which will alone be 

 indispensable to the systematic working araneologist. 

 Nor will it be possible (we are told in this vol.) to obtain 

 vol. iii. apart from the other two. 



.All that was said in the notices, above alluded to, of 

 Aols. i. and ii. can be again here repeated in praise of the 

 NO. 1.326, VOL. 51] 



execution of the work in this third volume. Chap. i. is 

 "on toilet, drinking, and social habits"; chap. ii. on 

 "memory, mimicry, and parasitism"; chap, iii, "bio- 

 logical, miscellany" ; chap. iv. "on weather prognostica- 

 tions, sundry superstitions, and the commercial value of 

 spiders' silk"; chap, v., "on moulting habits of spiders " ; 

 chap, vi., " regeneration of lost organs, and anatomical 

 nomenclature." On all these subjects there are many 

 most interesting and useful observations. 



In chapter i., p. i, speaking of spiders' habits of 

 cleansing themselves of objectionable matters by their 

 having a spiny armature of the legs and mandibles [fakes), 

 so evidently well adapted for the purpose, it is asked, 

 " Did the habit of cleanliness arise from the possession 

 of these implements, or were the implements developed 

 out of the vital necessity for a cleanly person.^" In the 

 first place, it suggests itself as hardly tenable to assume, 

 1) priori, such a vital necessity in respect to spiders, any 

 more than with regard to some Acarids, or the larva; of 

 certain insects, whose habit it seems to be not only 

 to need no cleansing, but to encourage the accumulation 

 upon their bodies of various kinds of adventitious and, 

 at times, of even excrementitious matter; but not to 

 dwell on this view of it, the case of the spiders 

 might perhaps be simply presented in this way. The 

 accumulation of dust, or soil, or what not about them, 

 arises mainly from their having clothing and spinous 

 armature, in which those substances become entangled 

 and retained, while at the same time those very causes of 

 the inconvenience become the means of obviating it ; 

 for we may take it that the first efforts of a sentient 

 being are to rid itself of whatever may adhere to it, to 

 its hindrance or annoyance ; in this process, whatever 

 existing portion of structure came handiest would 

 necessarily be the first used, whether, as in the case of 

 cows and other horned cattle, the lashing of its sides by 

 a heavily-tipped tail, or the muscular movements of the 

 ears, or the action of the hinder hoofs ; but it would 

 scarcely be argued, either, that the ears, tails 

 or hoofs of cows were developed just for the purpose 

 of ridding them of insect or other inconveniences, 

 or that the habit of so using them arose out of the 

 animals' possession of ears, tails, and hoofs. Nor can 

 we, it is conceived, argue either that spiders' 

 habits of using hairs and spines in cleansing themselves 

 arose from the possession of such implements, nor that 

 these implements were developed from those habits. \\\ 

 that we can say with any certainty, seems to be that 

 while hairs and spines, &c., were developed by various 

 means and for various ends, the more perfect adaptation 

 of soine of them for special functions would no 

 doubt be eflected by natural selection ; such, for instance, 

 as the development of the calamistrum on the metatarsi ot 

 the fourth pair of legs in numerous widely separated 

 genera, and even families of spiders, for the utilisation 

 of the silk-matter of the supernumerary spinners, which 

 last are always found correlated with the calamistrum. 

 Under the heading of " Burrowing Spiders," pp. 31-35. 

 we have a very interesting and important account of 

 trap-door nests made by Lycosid spiders ; those hitherto 

 known as " trap-door spiders " having been exclu- 

 sively of the family Theraphosida-. .-^ remarkable 

 account of a spider apparently voluntarily changing its 



