ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
183 
the author claims to have cleared up these points to some extent. The 
“ end-cells,” according to him, are better called transition cells, as they 
lead from the tracheal tubes proper to the “ capillary ” network. This 
latter is formed by slender nucleated cells, often with an intracellular 
lumen, and according to the author, probably constituting a respiratory 
epithelium. The author finds that both large and small tracheae may 
penetrate the gland-cells. 
Ergatogynous Forms in Ants and their Explanation.* — Under 
this heading Herr E. Wasmann has a somewhat comprehensive paper, 
which besides an account of his observations on the subject, contains 
discussions as to the bearing of the facts on theories of evolution, and 
on comparative psychology, as well as a polemic against Haeckel’s 
monism. 
Wasmann distinguishes six types of ergatogynous transition forms, 
to all of which he gives special names, and whose characters he discusses 
in detail. As compared with hermaphrodites, ergatogynous forms show 
in the first place considerable uniformity of occurrence ; they do not, 
occur in all species, but one type has frequently a strong tendency to 
appear in a species. Secondly, in some species they are extraordinarily 
common, which is never the case with hermaphrodites. Finally, they 
are contrasted with hermaphrodites in being almost always symmetrical 
while the latter are usually markedly asymmetrical. On these grounds 
the author concludes that ergatogynous forms do not owe their origin to 
the same causes as monstrosities. His theory as to their cause assumes 
the presence in the fertilised ovum of a double Anlage — that of the 
queen and the worker; these respond differently to developmental 
stimuli, e.g. to food, and the different intermediate forms between queens 
and workers therefore owe their characters to the instinct of the w r orkers, 
which leads them to supply the larvrn with food of certain quantity or 
quality. 
The author opposes Spencer’s theory as to the direct influence of 
food, and professes himself an adherent of a modified Weismannism, 
holding that variations occur in definite directions, and are then sub- 
jected to the influence of natural selection. 
Muscles of Hymenoptera. - ]* — M. Ch. Janet describes the muscles of 
ants, bees, and* wasps. Each consists of a group of fibres diverging 
from a tendon, which is an integumentary invagination. Each fibre 
may be regarded as a multi-nucleate cell; the sarcolemma represents 
the cell-membrane, and the longitudinal and radiating filaments lie in a 
nutritive filling substance. The radiating filaments ( filaments rayon- 
nants ) are formed of an exceedingly elastic substance, and serve to 
sustain the longitudinal filaments, to transmit the nervous stimulus to 
them, and to bring them back into position after contraction. Janet’s 
account of the minute structure agrees on the whole with van 
Gehuchten’s. 
New Species of Chermes.f — Herr M. Cliolodkovsky, w r hile con- 
tinuing his studies on the species of Chermes which infest the larch, has 
* Biol. Centralbl., xv. (1895) pp. 606-22, 625-46. 
t Comptes Reudus, cxxi. (1895) pp. 610-3 (20 figs.). 
X Zool. Anzeig., xix. (1896) pp. 37-40. 
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