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at one time. They are usually arranged in pairs, and I think it is not unreason- 
able that two act at a time, and that when the secretion of these is exhausted, 
the next pair come into action, and so on. The thread is of two kinds, or rather 
composed in two different ways, depending probably on the volition of the animal. 
The first is simple and smooth throughout its entire length ; and forms the longitu- 
dinal portion of the web, the other is studded throughout by minute globules or 
knots, as it were, of the silk secretion, which give it an adhesive character, these 
form the tranverse threads of the web, and give solidity to the structure. It 
appears to me that the difference in the two threads is caused solely by the first 
being spun from as much of the secretion as is emitted at one time, and that the 
other is the result of successive supplies of the fluid ; each emission being marked 
by the formation of one of the knots or globules. There is no real difference in 
the [secretion composing the [two threads, and I cannot but think that the above 
is the true explanation of the phenomenon. 
The threads of spiders' silk are very fine, the simple ones are about the l-1000th 
of an inch in thickness, the glutinous ones rather more, and yet each of these is 
made up of a large number of fine filaments, equal of course to the number of 
tubercles in the mammulaa which spun them. A single web contains sometimes 
300 threads or more ; so elaborate is the seemingly simple snare a spider sets to 
catch its prey. 
Such is a short, and I fear very imperfect sketch of the alimentary system of 
Tegenaria civilis. As an excuse for some of its shortcomings, I may say, that in 
giving this account I have been very much left as it were to my own resources. 
The descriptions of the alimentary system of spiders given in various works I 
consulted, differed so much from each other, being frequently directly con- 
tradictory, and that on some not unimportant points, that I soon found they were 
but lame supports to rest upon. I was, therefore, obliged to see and examine for 
myself, and the results such as they are, I have here given. 
The Vice-President remarked, apropos of the concluding portion of 
this paper, that this examination by members for themselves was most valu- 
able, and deserved the greatest encouragement. 
A Visitor enquired whether the separate filaments of which the thread 
of the spider was composed simply adhered together, or were twisted in a 
rope-like form ? 
Mr. Ponton was unable to answer the question definitely, but believed, 
both on a priori grounds, and from his observations, that they were simply 
adherent. 
Mr. T. II. Yabbicom said he had on one occasion been able to separate 
the filaments, which he could not have done had they been twisted. 
Mr. S. H. Swayne observed that the fact noticed by the author, namely, 
that the liver was composed of separate glandular bodies, rather than of 
a glandular mass, had been observed in other animals also. 
Mr. J. J. Hanson, of Weston-super-Mare, then read a paper on the 
Anatomy of the Actinias, illustrated -with diagrams. 
The position of the Actinia in the Animal kingdom was first pointed out. 
It belonged to the sub-order Zoantharia malacodermata, class Actinozoa, 
sub-kingdom Coelenterata, the members of which were the lowest animals 
