ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 59' 
of the body at the egg-nauplius stage leads to the ultimate separation of 
the embryonic exuviae. There is an anterior budding zone between the 
labrum and the thoracico-abdominal fold. It gives rise to the two pairs 
of maxillae, whereas the posterior budding zone gives' rise to the 
maxilli pedes and walking-legs. The second maxillae have a marked 
inward direction of growth — a recurrence of an ancestral character. 
Coelom sacs are found, in most cases indistinctly, at the bases of the 
appendages. They are larger posteriorly. The yolk cells are first 
formed from the blastoderm ; they have nothing to do with mesoderm ; 
they never turn into blood cells or connective tissue cells ; they act on 
the food-yolk as the mid-gut does, and may be grouped under the 
endoderm. J. A. T. 
Surprising Appearance of a Cyclops Species. — Rudolf Neubaur 
(Zool. Anzeig., 1921, 52, 161). Report of the abundant occurrence of 
Cyclops distinctus, regarded by Schmeil and others as a hybrid between 
C.fuscus and C. albidus. It was a rarity to Schmeil, who found only 
three females. But about 1912 Neubaur found this large and strikingly 
coloured species in abundance near Halle, and in the ten years that have 
elapsed since then he has found it plentifully in many places (e.g. Plon, 
Holstein, Berlin). It could not have been overlooked before, and it 
must have had an extraordinary prosperity since Schmeil’s monograph 
of about a quarter of a century ago. J. A. T. 
Transition Forms between Species of Copilia. — Carl Lehnhofer 
(Zool. Anzeig ., 1921, 52, 232-8, 7 figs.). Discussion of transitions 
between the males of Copilia quadrata Dana and C. lata Giesbr., especially 
as regards the antennae. The intergrades suggest continuous variability 
rather than hybridization. J. A. T. 
Annulata, 
Metabolic Gradient in Annelids. — Libbie H. Hymam and Albert 
E. Galicher (Journ. Exper. Zool ., 1921, 34, 1-16, 3'figs.). By means 
of the susceptibility and electrical methods, evidence has been accumu- 
lated which clearly indicates the existence of a double metabolic gradient 
in the Oligochaet and Polychaet Annelids. According to this evidence, 
the anterior and posterior ends possess the highest metabolic rate, and 
from these ends the rate decreases towards the middle regions. In the 
majority of forms the posterior end has a higher metabolic rate than 
the anterior end. The paper includes direct determinations of the 
rate of oxygen consumption per unit weight of pieces from anterior, 
middle, and posterior regions of the Oligochset Lumbriculus inconstans 
and also from the Polychests Nereis virens and N. vexillosa. The 
results of these determinations are that the posterior pieces of these 
species consume the most oxygen per uuit weight per unit time, the 
anterior pieces less, and the middle pieces least. The results, therefore, 
confirm the conclusions drawn from other methods and establish beyond 
reasonable doubt the existence of a metabolic gradient in these forms. 
J. A. T. 
New Type of Nephridia Found in Indian Earthworms of the 
Genus Pheretima. — Karm Narayan Bahl (Quart Journ. Micros. Sci ., 
