STRUCTURE AND DEVELOPMENT OF LOXOSOMA. 285 
organ in the bud ; and it appears to me to have no real con- 
nection with the budding processes. 
In L. crassicauda, L. Leptoclini and L. Tethyae there 
is certainly no such “ Knospenstock” as that described by 
Schmidt. In the woodcut fig. 2, on p. 75 of Schmidt's second 
paper the generative organs of a male L. pes have probably 
been represented ; o is in this case the testis, and the vas 
deferens is not indicated. Schmidt’s attempt to elucidate the 
nature of the two pairs of bodies described by him respectively 
as “ testes” and “ bud-rudiments” can thus hardly be con- 
sidered successful, and I am unable myself to throw any fresh 
light on the nature of these problematical organs of L. pes. 
Part 3. — The Development of Loxosoma. 
Our present knowledge of the embryology of Loxosoma 
is exceedingly limited, in spite of the statements of Vogt, 
Barrois, and others on the subject. That of Pedicellina 
has, however, been most accurately worked out by Hatschek 
(14), whose account I can confirm in its main features, with 
the exception of that part which refers to the development and 
the nature of the “ dorsal organ,” his “ Entodermsackchen.” 
My study of the development of Loxosoma has been made 
almost entirely by means of sections passing through the 
embryos in various planes. 1 L. Leptoclini differs from 
L. Tethyae in possessing two specialised diverticula of the 
posterior portion of the vestibule, one on each side of the 
intestine, which by its projection as a large longitudinal ridge 
(covered of course by ectoderm) into the vestibular cavity, 
gives rise to the two diverticula. In these the earlier stages of 
development take place, the older embryos, however, escaping 
into the main vestibular cavity, and no doubt nourishing them- 
selves on food particles brought to the vestibule by the cilia 
1 The material was preserved with osmic acid, picric acid, or corrosive 
sublimate ; the best staining of the embryos was obtained, after cutting, by 
means of Mayer’s method for fixing sections on the slide (39). In this case, 
hematoxylin, picrocarmine, or picrocarmine followed by hematoxylin gave 
the best results. 
