Miscellaneous. 159 
a seminal receptacle, which is always empty. The ovaries are com- 
posed of a few tubes, always destitute of ova. In those herma- 
phrodites of which the abdomen presents exactly the form peculiar 
to the drones, the copulatory apparatus exists in as complicated a 
form as usual ; the vas deferens and the testes are also well formed, 
and the latter are full of spermatozoids. 
A frequent form of hermaphroditism consists in the simultaneous 
presence on each side of a few testicular coils and ovarian tubes, 
whilst the epididymis and male copulatory apparatus are well deve- 
loped, and an imperfect poison-apparatus is also present. In this 
case spermatozoids are formed, but no ova. 
It is interesting to note that these hermaphrodites are seized by the 
workers at the moment of their issuing from the cells, and thrown 
pitilessly out of the hive. Their integuments being still soft, they 
cannot fly, and consequently soon perish. The queen of the hive 
which furnished these hermaphrodites is of the pure Italian breed, 
and five years old ; she presents no abnormal appearance externally. 
Professor Siebold, although unable positively to explain the mode 
of production of these hermaphrodites, does not consider that they 
present a phenomenon incompatible with the parthenogenetic theory 
of Dzierzon. In other animals the semen givesthe impulse to the 
development of the egg; the result of the influence of the semen of 
the drone is to impress the female character upon the ova, which, 
if not fecundated, would produce male individuals. The author 
thinks that we may assume a certain minimum quantity of semen to 
be necessary for the fecundation of an egg. In most animals a 
quantity of semen inferior to this minimum, of course, exerts no action, 
and the egg is not developed ; but in bees, whose ova are capable of 
development without fecundation, things must go on differently. 
Normally fecundation transforms the male egg of the bee into a fe- 
male egg. This conversion probably requires the action of a certain 
number of spermatozoids; but if some accidental circumstance prevents 
the necessary quantity of spermatozoids from penetrating the vitellus, 
the ege, without being completely converted into a female one, will 
nevertheless be disturbed in its development in such a way as to pro- 
duce a mixture of the characters of the two sexes.—Siebold and 
Killiker’s ‘ Zeitschrift, 1864, p. 73. 
On the Aérial Roots of the Orchidee. 
By H. Leirers. 
The cellular tissue forming the outer layer of the aérial roots of 
tropical Orchidez, and described by Schleiden under the name of 
the “‘root-envelope,” is neither placed above the epidermis, as sup- 
posed by Schleiden and Chatin, nor, as asserted by Schacht and 
Oudemans, the outer part of the primary bark, and therefore covered 
by the epidermis, but a cellular structure in the epidermis. The 
root-envelope is not developed from a cellular tissue already deposited 
beneath the epidermis by the primitive parenchyma of the vegetative 
cone, but subsequently and directly from the epidermis by the divi- 
