ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
507 
greatly developed, and apparently of much functional (nutritive) im- 
portance. 
(2) Salpa musculosa-punctata. As in S. zonaria , &c., there seems to 
be a characteristic cleavage stage consisting of six blastomeres, two 
larger, four smaller. This stage has a follicular envelope, separated 
from the blastomeres by a layer of kalymmocytes. The blastomeres 
multiply and show two kinds — (a) small and clear, (b) large and dull ; 
in the latter yolk-particles become deposited. Korotneff then describes 
the so-called amnion-cavity, the origin of the ectoderm, the cloaca and 
pharyngeal cavity, the heart and pericardium, &c. 
Kemarkable Ascidian.* — Dr. A. Willey has discovered an Ascidian 
which, he thinks, throws some light on the form described by Sluiter as 
Styeloides abranchiata. In this form, it will be remembered, the branchial 
sac and intestine were absent, but the condition of the animal in other 
respects was such that Sluiter was led to suppose that this must be the 
normal state of things, and he founded a new genus accordingly. 
Herdman has observed that this case is so exceptionally remarkable, 
that he cannot help suspecting that the single specimen was merely an 
individual abnormality. Dr. Willey has found a new species which is 
remarkable for the faculty which it possessed of evisceration, and he 
calls the form therefore S. eviscerans ; he had had them for a short 
time in a vessel where everything was fresh and in good condition, and 
he suddenly discovered a number of digestive tracts lying at the bottom. 
On inspecting the ascidians he found that they were all living, and in a 
healthy condition. Eventually, however, he actually observed the pro- 
cess of evisceration taking place ; after it was over, the animal presented 
a perfectly normal and healthy appearance. But, so constant is this 
ejection of the digestive tract, that if it is desired to preserve specimens 
intact, they must be placed in alcohol immediately after capture. On 
dissection of an individual which had ejected its sac and intestine no 
sign of any laceration whatever was observed, and, undoubtedly, in 
ignorance of the habit, one would be tempted to suppose, as Sluiter did, 
that the absence of an alimentary canal was the normal condition. 
INVERTEBRATA. 
Animal Parasites of Chickens, Turkeys, and Ducks.j — Mr. A. 
Hassall has prepared lists of the animal parasites of these three domestic 
birds. In these lists the author does not commit himself as to the 
validity of any species or genus, or to the validity of any specific or 
generic name. The names given are those adopted by the most recent 
authorities, but it will be years before all of these forms can be properly 
studied. Parasites are found among the Protozoa, flukes, tapeworms, 
roundworms, mites, and insects. 
Phenomena of Fertilization.^ — Dr. 11. von Erlanger has studied 
these in the ova of Tardigrada, Echinoids, and Ascaris megalocejphala , 
and has been successful in sectioning the last-named. We cite some of 
* Quart. Journ. Micr. Sci., xxxix. (1896) pp. 161-6 (4 figs.). 
t U.S. Department of Agriculture, Bureau of Animal Industry Circulars, No. ix. 
8 pp., No. xii. 4 pp., No. xiii. 8 pp. (1896). 
J Zool. Anzeig., xix. (1896) pp. 136-9 (1 fig.). 
2 n 2 
