PLATYHELMINTHES. 
Verm . 3 
les faunes profondes de la ' Mediterran<$e Ann. Mus. Marseille, Zool. i. 
pts. 1 & 2. 
On the Vermes of Cape Verde Islands, see De Rochebrnne, N. Arch. 
Mus. (2) iv. pp 228-287. 
Anatomy and Development. 
In a most valuable and suggestive article, A. A. W. Hubrecht (Q. J. 
Micr. Sci. xxxiii. pp. 349-368) discusses the apparent resemblance between 
the Nemer tinea and the Ancestral Form of the Chordata .” 
Francotte (3) describes the structure of Derostomum henedeni , sp. n., 
found at Audenne ; he regards the lacunae in the body as representing a 
true coelom, and reports the presence of haemoglobin in the anterior part 
of the body. 
Gaffron (4) finds that the two ventral nerves of the Trematoda unite 
at the hinder end of the body, as do also the dorsal, but that the lateral 
nerves break up and fuse with one another. All the longitudinal trunks 
are regularly connected with one another by a system of commissures. 
In Solenophorus (5), the ganglia of the scolex are arranged in two planes, 
in the form of a cross ; the two longitudinal trunks in the strobila take 
their origin from the median ganglia of the scolex, and seem to represent 
an undifferentiated ventral medulla. 
Hubrecht’s (7) Pseudonematon nervosum has a nervous system which 
forms a continuous layer around the body, lying just inside the layer of 
circular muscles. There is no cephalic enlargement. This paper is 
reviewed by Minot (Science, ii. p. 382). 
Jijima (9) regards tho space botwoou the branched connective-tissue 
cells of the mesenchyma as representing the body-cavity. Mucous and 
salivary glands can be distinguished. The cocoon is not formed in the 
uterus, but by a special glandular organ. The primary excretory canals 
of Dendroccelum lacteum unite with one another by a transverse vessel, 
placed in front of the head. 
His observations on development (8) in many points confirm those of 
Metschnikoff (14), who, though particularly dejirous of finding an ex- 
planation of the intercellular mode of digestion, sought it in vain. His 
most striking observation is that of the development of a pharynx before 
the definite differentiation of the ectoderm and mesoderm ; but analo- 
gous embryonic adaptations have, of course, been observed elsewhere. 
Schauinsland (18) insists on the close resemblances between the de- 
velopmental histories of the Trematoda and of the Mesozoa. 
Villot (20) divides cystic stages into true cysticerci and cysticercoids ; 
the latter fall into two groups, according as the caudal vesicle is formed 
by an endogenous or exogenous mode. To the former belong Polycercus 
(represented by the form found in Lumhricus terrestris) and Monocercus 
(by the so-called Cysticercus arionis) ; to the latter belong Cercocystis 
(cystic worm of the larva of Tenebrio molitor ), Staphylocystis (for S. 
bilarius and S. micracanthus ), and Cryptocystis (for the form found in the 
visceral cavity of Trichodectes cams'). The steps between the complete 
independence of the proscolex and cystic stages, as seen in Urocystis and 
