ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
G81 
accepted, and the relations of tlie families are sliown by the annexed 
table. 
Metamorphosis of Freshwater Ostracoda.* — Prof. C. Claus finds 
that the Ostracoda undergo a metamorphosis, for not only have they, at 
different stages of their free life, a different form of shell, but they 
exhibit differences in the number and form of their appendages, and 
they have several provisional arrangements. In Cypris nine successive 
stages are to be distinguished. The youngest larva is a shell-bearing 
Nauplius-larva, with the three anterior pairs of ajipendages, the third of 
which is not a mandible, but a leg. It is not till the second stage that 
the mandibles take on their definite form, and the leg then becomes a 
mandibular palp. At the same stage there appear the Anlage ” of the 
maxillae, and the f ureal stump with its hooks. The second pair of 
maxillae appear in the fourth stage, and come into function in the fifth. 
The position and insertion of the hinder tuft of hooks, which is present 
in all stages of development, undergo several changes, for at first it is 
borne by the second pair of maxillae, then by the furcal stump, then by 
the maxillip, and finally (and permanently) by the anterior pair of legs. 
The hinder pair of legs appears in the sixth stage ; in the seventh 
all the appendages have their permanent conformation, and in it the first 
signs of the generative organs become apparent ; their further develop- 
ment and sexual differentiation occur in the eighth stage. The so-called 
abdomen or post-abdomen is the furca, and is first seen in the second 
stage. In the fifth the hepatic tubes grow into the shell. The Ostracoda 
have a kind of shell-gland. The setal appendages of the shell are 
connected with a system of fine threads and cells. 
A Flying Copepod.j — Dr. A. Astroumoff reports that, one morning 
early, with a calm sea and clear sky, he saw a number of the small green 
Pontellina mediterranea rise from the water, make springs in the air, 
describe a long curve, and fall again into the sea. This unusual mode 
of locomotion is effected by the strongly pinnate limbs, and has probably 
some connection with the commencement of the process of eedysis. 
Vermes. 
Cerebral Physiology of Worms.J — Dr. J. Loeb finds that if 
Thyscinozoon Broccliii be cut across transversely the anterior half moves 
spontaneously, but the posterior half has to be stimulated. If instead 
of making this cross cut the longitudinal nerves are cut through, the two 
pieces being left connected on one side by a thin bridge of substance, 
the aboral piece continues to take a co-ordinated share in progressive 
movement ; alterations of movements start, however, only from the oral 
piece, and are only after some time communicated to the aboral piece. 
If Planaria torva be cut across, the aboral half, which contains no 
brain, moves quite as fast as the oral half. Increase of intensity of light 
stirs the normal animal to movement, and this peculiarity may be seen 
in the separate hinder pieces. The hinder separated half of Cerebratulus 
marginatus does not, like the anterior half, try and bore in the sand. 
If a Nereis be cut into several pieces it is the oral part only that is 
* Zool. Anzeig., xvii. (1894) pp. 325-30. f Tom. cit., p. 369. 
X Arch. Ges. Physiol., lvi. pp. 249-69. See Zool. Centralbl., i. (1894) pp. 554-6. 
