114 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
hairs, and the linear thickenings of the tegument, in approaching these 
points, surround them in concentric circles. I have heretofore suggested 
that all action of the muscles upon the abdominal tegument may have 
much influence in the distribution of color for the formation of various 
patterns which mark spiders.? 
Fig. 77 represents the tarsus and metatarsus of a Lycosid foot (‘Taren- 
tula), taken from the rejected skin. The tendons by which the tarsus and 
claw are moved are shown within the leg, and one sees the 
thickening of the tendons (e.t) at their free ends upon which 
the muscles are inserted. The claw and the entire dentition 
thereof, as may be seen, have left a perfect cast in the moulted tegument. 
The tendon passes from the claw in the form of a thick 
double cord, traversing the tarsus apart and uniting at the 
’ articulation with the metatarsus, which joint is traversed 
nearly to the articulation with the tibia, where the cords 
join with the short stout muscles in- 
serted into the cuticle at that se 
point. The silk glands in ; 
moulting undergo changes 
both in form and number, as with the 
tubuliform glands of tarentula shown 
at Fig. 78, after the second and third 
moults. Three different forms of glands 
appear (gl 1, gl 2, gl 3), corresponding 
possibly with the ampullate, tubuli- "."%, Sf Hage ae 
i form, and pyriform glands of Epeira, — second and third moutts. 
1G. 77. Moult of 5 : 
final joints of a Ly- Adult spiders of the two sexes, according to Wagner, do 
rei foot, show not always possess the same silk glands. The females have 
(e.t) that move the glands not observed in the males, which this author be- 
tarsus and claw. Jieves serve to supply the cocooning silk. However, in the 
earliest stages of life the silk glands of the male and female are alike. 
Tendons 
of Foot. 
Silk 
Glands. 
ml, 
These physiological facts in the moulting processes of spiders Mr. 
Wagner has himself thus summarized: 1. The rejection of the old skin 
Sum- 
pais ondary one. 2. The processes of a moult, in some of their features, 
commence a comparatively long time before, and end after the 
rejection of the skin and in connection therewith. 38. The spider, partly 
before casting off the old skin, partly at the moment of the act, and even 
for a brief period afterward, is deprived of some of its faculties: of sight, 
1 Proceed. Acad. Nat. Sci., Philadelphia, 1888, page 173. 
constitutes only a part of the moulting process, and that a sec- .: 
as est 
