ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
155 
making a model reconstruction from his sections. His conclusion cor- 
roborates that of Reichert (1837) that the malleus and incus develope 
from the cartilage of the first visceral arch. As to the stapes, ho 
maintains that the hyoid cartilage contributes to its development, or, 
very probably forms the whole of it. 
Degeneration of Ovarian Ova in Lizards.* — Herr Strahl has studied 
this in Lacerta viridis. Females wore kept apart from males, and the 
mature ova being undischarged underwent degeneration. The nucleus 
becomes vacuolated and disappears ; the polar protoplasm of the ovum 
is divided into small pieces ; the yolk becomes more fluid ; leucocytes 
invade the walls of the follicle and absorb yolk-particles, and the whole 
egg becomes smaller. Further stages were not observed, for the lizards 
could not be kept alive for more than a year. 
Spermatogenesis in Sauropsida.f — Herr C. Benda finds that the 
archiplasm in the mammalian spermatide consists (a) of a pale homo- 
geneously stainable portion (which comes to nought), and ( b ) of a 
vacuole with a deeply stainable body, which forms the apical cap of the 
spermatozoon. The chromatoid accessory body discovered by Hermann 
has two parts ; one, often annular, comes into relation with the spiral 
thread of the intermediate piece of the spermatozoon ; the other part 
seems to become the terminal knob of the axial thread. It is doubtful 
whether this chromatoid accessory body be archiplasmic. 
The ripe spermatozoon of the sparrow has an anterior and a posterior 
portion in its head ; the anterior portion is stained green or violet with 
acid anilin, the posterior portion is stained red with basic anilin. In 
the spermatide the archiplasmic sphere lies in a small depression of the 
nucleus, but increases until it is as large as the nucleus. The two lie 
apposed like two hemispheres. Near the boundary between nucleus and 
archiplasm lies the extremely minute accessory chromatoid body. The 
archiplasmic hemisphere comes to occupy the proximal or anterior pole, 
and a new structure — a deeply stainable grain — appears within it ; the 
accessory chromatoid body comes to lie at the distal or posterior pole. 
Further stages show that the anterior portion of the head of the 
spermatozoon is due to the archiplasm. The grain within the archi- 
plasm seems to disappear. At the distal pole there appears the tail. 
Most of the chromatoid body lies as a short rod at the origin of the tail, 
but it is likely that a special part is separated off as the terminal 
knob. 
Development of Vertebral Column of Anura.ij:— Herr C. Hasse finds 
that the toads have, like fishes and Urodela, not only a cuticula chordae 
(or elastica interna), formed from and surrounding the notochord, but 
also a cuticula sceleti (or elastica externa), which is formed from the 
skeletogenous layer. Frogs are, like the Amniota, without a cuticula 
sceleti, and have only a cuticula chordae. The Anura are thus inter- 
mediate between fishes and Urodela, in which there is a special cuticula 
sceleti, and the Amniota, in which there is not only no cuticula sceleti 
but a marked reduction of the cuticula chordae. 
* Verhandl. Anat. Gesell., vi. (1892) pp. 190-5. f Tom. cit., pp. 195-9. 
X Zeitschr. f. Wiss. Zool., lv. (1892) pp. 252-64 (1 pi.). 
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