. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. REGENERATION OK LOST ORGANS. 123 (Fig. 85, ar.) It afterwards increases from one end to the other more equally in length than in width, and nineteen or twenty days afterward, with a tarentula of middle age, it presents an organ long, almost com- pletely formed, gradually diminishing from the hase towards the extremity, and much twisted. The articulations of this organ are formed successively from the base towards the periphera,
. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. REGENERATION OK LOST ORGANS. 123 (Fig. 85, ar.) It afterwards increases from one end to the other more equally in length than in width, and nineteen or twenty days afterward, with a tarentula of middle age, it presents an organ long, almost com- pletely formed, gradually diminishing from the hase towards the extremity, and much twisted. The articulations of this organ are formed successively from the base towards the periphera, the second forms after the first, the third after the second, etc. Consequently, this process is accomplished nearly as that described by Clarapede1 for Lycosids in their embryonic period. Thus is accomplished successivel}' the isolation of the tissues be- tween the base of the joint and its extremity. Pending this; near the base of the foot, one readily observes muscular fibres (Fig. 83, pt 1, and ), and on the surface a chitinous membrane (), a little elongated at the base. (Fig. 83, pt 2.) Here one does not notice that the muscles are isolated, or anything but chitinous teg- ument (); the tip of the foot (pt 3) only the chitino- genous layer is isolated. Sections of this new organ at different stages of its development show that it first originates the ma- trix of the papilla; its cells at its periphera are in im- mediate contact with the blood, environing the neo- formation. In the mean- time, as the neo- 0 . formation grows, the exterior layer of the matrix is more and Hairs. more feebly colored ; at this epoch the superficial part may be regarded as chitinous tegument. The tegument is very fine, and does not form simultaneously upon all the neoformation, but gradually, its growth extending from the base towai'ds the periphera. Thus the neofor- mation presents, from the exterior inwardly, first, a chitinous tegument; second, a chitinogenous layer beneath it; t
Size: 2477px × 1009px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
