124 



AMERICAN SPIDEKS AND THEIR SPINNINGWORK. 



matter of those tissues wliich are atrophied and undergo the regenera- 

 tion of the fat henefits the organism in three ways : First, in transmitting 

 that matter by means of the amoeboid blood cells, which assim- 

 •^®**"*'' ilate and plasmatically digest it,i essentially after the regeneration 

 tions. ^^ grease becomes less intense, and even appears to have touched 

 its limit. Second, in transmitting the matter by means of the red blood cells 

 which assimilate it by absorption. Third, by means of globules of grease, 

 which in themselves present certain forms whose role is to transport the 

 nutritive matter into the whole body. 3. It is doubtful whether, without 

 cooperation of blood cells, regeneration of fatty tissues would proceed to 

 complete disappearance; if it could occur it would be after a considerable 

 and indefinite time. 4. Tlie process of degeneration of muscular tissue in 

 spiders, in its general traits, suggests that of vertebrate animals. 



VI. 



In the descriptive matter to which the second part of this volume is 

 devoted certain terms and abbreviations are used that require explanation 

 f^R and illustration, which it seems best to 



Nomen- insert together at this point for eon- 



MR 



V 



es 



.ocq 



SR 



-sr 



ar 



Fig. 87. Face of orbweaver ; cly, 

 clypeus ; es, eye space ; MF, MR, 

 midfront and midrear eyes; SF, 

 SR, sidefront and siderear eyes ; 

 oc.q, ocular quad ; v, vertex. 



clature of 

 Descrip- 

 tion. 



venience of reference. The quadrilat- 



eral described by the middle group of 

 four eyes (MF and MR) is called the 

 ocular quadrilateral, or more commonly " ocular 

 quad " (Fig. 87, oc.q), as at once a brief and 

 definitive term. The ocular area or eye space 

 (es) is that part of the face over wliich the eight 

 eyes are distributed. The curvature of the eye 

 rows forms an important characteristic in deter- 

 mining species. The rows are said to l^e pro- 

 curved when the concavity is directed forward toward the mandibles, and 

 recurved when the concavity is directed backward. When the row is 

 straight, or nearly so, it is said to be " aligned," or nearly so. In deter- 

 mining the curvature the ^,=->^ ^i'^~~°V 



T 



Fii;. 90. 



^^ ■ eye rows have been looked 

 at from the front, and a little be- 

 low the horizon of the front row. 

 It is often difiicult to determine the 

 exact curvature, especially as it dif- 

 ers with the point of vision. In 

 Fig. 88 the front row of eyes is recurved, the rear row slightly procurved ; 

 in Fig. 89 the front as well as the rear row is^procurved ; in Fig. DO the 

 front row is nearly aligned, the rear procurved. 



Fli^. 88. Fl.i. 89. 



Curvature op Eyes. 

 Fig. 88. Front row recurved, rear row procurved. Fki. 89. 

 Both rows procurved. Fig. 90. Front row nearly aligned, 

 slightly recurved, rear row procurved. 



1 See Wagner, " Du Sang des Araignees." 



