46 
W. F. rUKCELI-. 
nucleated homogeneous mass, which stains very deeply with 
carmine, and is, histologically, readily distinguishable from 
all adjacent tissues. All the cells of the ventral longitudinal 
muscles become subsequently attached by each end to these 
entochondrites only, which in turn firmly adhere to the bases 
of the ectodermal cells of the deepest part of the contact- 
area described above, and provide us with a certain means of 
locating- these latter cells long after the subsidence of the 
appendages. It should be noted that the entochondrites are 
much less extensive at first than the ectodermal areas (ar. 7, 
etc., figs. 6 and 27) Avith Avhich the ends of the forming 
muscles Avere originally in contact. 
From Avhat has just been said, there can be no doubt that 
the places of attachment of the entochondrites inserted in 
each ventral longitudinal muscle are serially homologous, a 
fact Avhich may also be readily inferred from a glance at 
fig. 41, Avhich represents the stage shortly before hatching. 
From this figure it may also be observed that scA^eral other 
muscles are attached to the entochondrites {f. 7-11), in addi- 
tion to the segments (r. 1. m. 7-11) of the great longitudinal 
muscles as, for instance, (1) a long dorso-A’entral muscle 
{<1. V. m. 7-10); (2) a short, oblique muscle (p. oh. vi. 8-11) 
running- obliquely foi-Avards and attached near the middle of 
its segment to the hypodermis Avithout the interposition of 
an entochondrite ; and (8) a corresponding oblique muscle^ 
{a. oh. r/i. 8 and 10), running obliquely backAA-ards, present in 
segments 8 and 10. In Agelena lab 3 "rinthica I also 
treffeu, so liildet sich an der Stelle ihrer Beriilu-uiig eiiie Seliiie meso- 
dei-iualen Ui-sjn-ungs.” To my mind it does not matter whether the 
muscles are in a line or meet at an angle, the essential conditions being 
only that the ends of tivo or more muscles should meet at one 
spot and that that spot should be on tlie basal surface of 
the hypodermis. When muscles are attached singly to the hypo- 
dermis they do so directly AA-ithout the intervention of an entochondrite. 
‘ I have called this muscle-series and that pi-evioAisly mentioned the 
anterior {a. oh. m.) and posterior oblique muscles (p. ub. w.), because 
they lie in the anterior and posterior regions resjAectively of their 
soinites. 
