124 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



Deduc 

 tions. 



matter of those tissues which are atropliied and undergo the regenera- 

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

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

 ilate and plasmatically digest it,^ essentially after the regeneration 

 of grease becomes less intense, and even appears to have toviched 

 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. The 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 



and illustration, which it seems best to 

 Nomen- insert together at this point for con- 

 c a ure o ypj^jgj-^(.g ^f reference. The quadrilat- 

 tion ^^^^ 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 which the eight 

 ciypeus; es, eye space ; MF, ME, gygg ^re distributed. The curvaturc of the eye 



midfront and midrear eyes ; SF, . . . . , 



SE, sidefront and siderear eyes; rOWS formS au UUportant characteristic 111 dctcr- 



oc.q, ocular quad; V, vertex. mining spccics. The rows are said to be 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 



MR 



V 



MR 





MF 



SR 



SF 



or 



Fig. 87. Face of orbweaver ; cly, 



rw. 88. 



Fig. 90. 



' eye rows have been looked 

 at from the front, and a little be- 

 low the horizon of the front row. 

 It is often difficult 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. 90 the 

 front row is nearly aligned, the rear procurved. 



Fl(i. 89. 

 Curvature of Eves. 

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

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

 slightly recurved, rear row procurved. 



' See Wagner, " Du Sang des Araiguees." 



