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SUMMARY OF CURRENT RESEARCHES RELATING TO 
form of a thin and transparent membranous sac ; the four penultimate 
abdominal segments appear to be extended and stretched to the limit of 
the extensibility of all their interarticular membranes, and the posterior 
half of the abdomen appears, therefore, to be the region which gives 
lodgment to the main mass of the brood-pouch. The arrangement is 
much more like that of the white-ant queen than of the viviparous 
Coleoptera. The species belongs to the genus Notanatolica , and may be 
called vivijpara. The nature of the brood-pouch, the habits of the larvae 
— whether aquatic or terrestrial — the male, and the form of the larva- 
case, are important points as to which information is desirable. 
Ovarian Envelope of Phyllium.* — M. L. F. Henneguy has examined 
the structure of the envelope of the ova of this orthopterous insect. 
The egg of P. crurifolium , from the Seychelles, measures 5*5 by 4 mm., 
and a vertical section, under a low power, is seen to consist of three 
zones ; the outermost is formed by large, irregular alveoli ; the median 
by thick, parallel fibres, which are set perpendicularly to the internal 
surface ; the innermost zone is compact in structure and striated. The 
outermost layer is very thick in the wings of the c ipsule which it forms 
entirely, and much thinner in the interalar spaces. It and the median 
zone represent the exochorion of authors, while the innermost corre- 
sponds to the endochorion. It is but rarely that the alveoli have the 
pentagonal or hexagonal form described by Murray and Joly ; their 
walls, the thickness of which is not constant, are formed of a homo- 
geneous substance of a chitinous nature ; the alveoli are filled with air, 
and contain no traces of protoplasm. The median zone, which does not 
seem to have been seen by Murray or Joly, is characterized by short 
fibres, equal in thickness, and set parallel with one another. The 
innermost zone has the most complex structure, for four or five different 
layers can be made out in it. The most external layer is very delicate, 
and homogeneous, and is set against the layer on the surface of which 
are implanted the fibres of the median zone. Next there is a layer 
which is finely and regularly striated, and the striae are perpendicular to 
the preceding layer ; this may, indeed, be divided into two layers, for 
the outer part remains colourless while the inner becomes rosy on 
treatment with safranin. These are followed by an irregularly striated 
layer, and this by one which is homogeneous. The second and third 
layers have a very remarkable crystalline structure ; when examined 
with polarized light they exhibit double refraction. They are very 
fragile, and break easily under the razor ; the lamellae thus formed have 
a calcareous appearance, but are insoluble in acids ; on treatment with 
potash the only apparent alteration is the loss of the double refraction. 
It would be very interesting to study, from the histological point of 
view, the structure of the egg-capsule of different Phasmidae, and the 
mode of formation in the genital passages ; it is difficult to conceive how 
so complex a tissue can be secreted by the walls of the oviduct and the 
ovigerous sheaths. 
The author repeatedly compares the egg to vegetable seeds, and he 
points out the interest of the fact that while the adult insect exhibits a 
mimicry of parts of plants the egg should do so likewise. 
* Bull. Soc. Philom. Paris, ii. (1890) pp. 18-25. 
