ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
777 
from the atrial aperture. Immediately after each set of eggs there came 
a little white milky jet, which, on examination with the Microscope, was 
found to be a mass of active spermatozoa. After two hours segmenting 
ova were found at the bottom of the dish which contained the Ascidian. 
It is possible that this self-fertilization occurs in some other species, 
though not in all. 
13 . Bryozoa. 
Gland-like Bodies in Bryozoa.* — Mr. A. W. Waters has found 
gland-like bodies in the avicularian chamber of various Bryozoa, but 
has studied them most satisfactorily in Lepralia foliacea , where he has 
observed them to be composed of small elongate cells, which are in some 
cases distinctly nucleated. Suboral glands are now known in a number 
of species, though they are by no means found in all. The present 
results are not complete, as the author has not yet been able to trace the 
early stages of these structures. 
<y. Brachiopoda. 
Development of Brachiopoda.j — Mr. C. E. Beecher gives a brief 
review of the known embryology of the Brachiopoda in the nomencla- 
ture of the stages of growth and decline which has been proposed by 
Hyatt ; the author desires to account for some of the differences 
presented by adult forms in the several divisions of the class, but our 
knowledge does not appear to be so complete as to enable him to come 
to any important generalizations. 
Arthropoda. 
o. Insecta. 
Appendages of First Abdominal Segment of Embryo Insects.t— 
Mr. W. M. Wheeler applies to these organs the name of pleuropodia for 
the purpose of suggesting their origin from foot-like organs, and their 
tendency, when fully developed, to take up a position on the pleural 
wall of the embryo. Summarizing his own results and those of other 
observers, he concludes that pleuropodia were at one time organs of 
considerable functional importance to the primitive Hexapoda. This is 
not only proved by the size to which they sometimes attain, as in Blatta , 
but by the variety of structure which they exhibit. In some orders they 
appear to be of constant occurrence, while in the Lepidopfcera and 
Hymenoptera they are as constantly wanting ; they are always derived 
from the ectoderm, and arise as appendages, which are serially homolo- 
gous with those of the thorax and abdomen. Sometimes they are formed 
by invagination, sometimes by evagination, and there are numerous 
varieties of form. The cells and nuclei of which they are composed 
increase in size, and usually become more succulent than other ectoderm 
cells ; they contain one or two cavities. No trachese, nerves, or muscles 
have been observed to enter into their composition ; a few mesoderm- 
cells, which are probably blood-corpuscles or fragments of mesenchyma- 
tous tissue, have been seen in the cavities of some pleuropodia. 
In some species the pleuropodia produce a secretion from the ends 
of their enlarged cells, which may be a glairy albuminoid substance, a 
* Journ. Linn. Soc. Lond., xxiv. (1892) pp. 272-8 (1 pi.), 
t Amer. Journ. Sci., xliv. (1892) pp. 133-55 (1 pi,). 
% Trans. Wisconsin Acad., viii. (1892) pp. 87-140 (3 pis.). 
3 G 
1892. 
