1864. | The Spiders of Great Britain and Ireland, 127 
its snare in about forty minutes, if it meet with no interruption. 
Mr. Richard Beck, in a paper read before the Microscopical Society 
in 1862, stated that, by examination with a lens of a spider in the act 
of spmning a geometric web, he had convinced himself that when the 
thread left the spinnaret no dots were apparent, but that the change 
was one which took place afterwards and gradually. At first, slightly 
thicker than ungummed threads, the viscid secretion soon began to 
form undulations, and eventually separated, forming globules, by mcle- 
cular attraction, at very regular and very minute intervals, It thus 
appears that a physical law produces the marvellous results formerly 
attributed to the direct agency of the spider. 
It will hardly surprise us to learn that these regular webs are 
constructed in absolute darkness, without the slightest irregularity of 
plan or defect of structure; nor that young spiders display in their 
first attempts the most consummate skill as the most experienced indi- 
viduals. Nor should the aérial flights of the aéronautic spiders be 
passed over in silence—excursions which appear to have a migratory 
instinct as their impulse. These flights are undertaken by the agency 
of long buoyant threads, which are not darted from the spinnarets, and 
thus propelled to a distance, as was long imagined, but simply ejected 
gradually, and carried upwards at the same time that they are solidified 
by the ascending current of air. 
To those who are acquainted with the garden-spider, the house- 
spider, and the money-spinner, and whose knowledge of Arachnology, 
perhaps, then meets with a termination, it will be matter of profound 
astonishment to hear that the laborious and indefatigable researches 
‘of Mr. Blackwali have resulted in the description of upwards of three 
hundred species of spiders as occurring in Great Britain and Ireland. 
These are distributed through only thirty-four genera, allowing there- 
fore an unusual number of species to a genus. Indeed, the genus 
Linyphia has thirty-three species; the genus Hpéira, thirty-one species ; 
Walcknaera, thirty-two species; and Neriéne, forty-eight. This is a 
muck larger proportion than usually falls to the lot of a well-consti- 
tuted genus, and probably it will hereafter be found desirable further 
to subdivide such comprehensive genera; although we do not for a 
moment call in question Mr. Blackwall’s judgment as to this present 
arrangement. There is another circumstance also which indicates 
that the practical study of the Arachnology of these islands is in its 
infancy, and that is the fact that the observers who have co-operated 
with Mr. Blackwall are so few in number, the chief being two or three 
gentlemen well known for their attachment to this branch of Zoology, 
viz. Mr. R. H. Meade, Rev. O. Pickard-Cambridge, Rev. Hamlet 
Clark, and Mr. J. Hardy ; while the cabinet of Mr. F. Walker, of the 
British Museum, has yielded many rare and interesting species; and 
Mr. R. Templeton has done much for Ireland. As a matter of course, 
the researches of these gentlemen could be conducted only over a 
limited extent of country, and the frequent repetitions of the same 
locality show at once the extreme and praiseworthy industry of these 
gentlemen, and the great need there is of energetic search in other 
parts of the country. Of course the vale of Llanrwst has been well 
