MATERIALS FOR A MONOGRAPH OF THE ASCONS. 333 
I may say at this point a few words about Woodland’s 
theory of the “righting ” of the triradiate systems. He states 
that even in the oscular tube the young triradiates of Sycons 
have an irregular orientation, which is later corrected by the 
action of direct stresses and strains on the wall of the sponge 
(1905, p. 265, footnote ; 1907 [2], p. 76). His observations do 
not agree with mine on various species of Leucosolenia. 
Both in the oscular tubes and diverticula, I have always 
found the youngest triradiates to have from the first the 
orientation normal to the region in which they are found. 
The best way to see this is to take pieces of sponges preserved 
in alcohol, mount them stained or unstained in Canada balsam, 
and examine them by polarized ght with crossed prisms ; all 
the spicules appear brilliantly illuminated and the young 
stages are clearly seen. JI must express my entire scepticism 
with regard to Woodland’s theory of ‘“‘righting.’ I believe 
the youngest spicules take from the first the position they 
have when full grown. That, at least, is my impression from 
the oscular tubes of Ascons. 1 suggest that the irregular 
orientation of the young triradiates in oscular tubes of Sycons 
is related to the numerous, closely set diverticula (radial 
tubes), continually bemg formed, in which a special arrange- 
ment of the spicules prevails, just as in Leucosolenia; and 
that it is comparable to the regions (w) where in Leuco- 
solenia also the orientation of the spicules is chaotic, in 
relation to beginning, or even to future, evagination of the 
body-wall. These chaotic regions might be expected to be 
far more numerous 1n a growing Sycon than in a Leucoso- 
lenia. Compare the long, smooth oscular tubes of Leuco- 
solenia (Pl. 21, figs. 104—107) with the young Sycon 
depicted by Maas (1900 [2], pl. x, fig. 7) ; his figure recalls 
the classical Diana of Ephesus. 
Woodland gives a figure (1905, p. 271, text-fig. 10) to illus- 
trate his theory that the body-wall is pressed in between the 
arms of the triradiates, so that “a groove is formed in line 
with each ray of the spicule along which the apical cell must 
tend to travel.” J can confirm the first part of these state- 
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