ZOOLOGY AND BOTANY, MlCllOSCOPY, ETC. 
167 
groups (1) Podalirius, (2) Antiphates, (3) Leosthenes- Anticrates- Ajax, and 
(4) Ajax-Policenes, be seeks to show bow tbe variations exhibit orderly 
progress along definite lines of evolution. Thus tbe ground-colour 
tends to pass from yellow into green; in (1) green appears at tbe roots 
of the wings ; in (2) likewise and also at tbe angles ; in (3) green pre- 
dominates, and that completely in tbe American forms; in (4) tbe same 
is true. The colouring depends upon a pigment, its alteration on con- 
stitutional and environmental conditions. But tbe regularity of variation 
is even more striking when tbe markings — bands, lines, and spots — are 
studied, tbe author’s contention being that all tbe variations are definite 
and progressive, sometimes towards greater complexity, but as often 
towards simplification. 
“ All tbe details, even tbe minutest, show that the origin of varia- 
tions, varieties, and species, depends throughout on orderly physiological 
changes in definite directions. Various characters change pari passu in 
correlative or kaleidoscopic modifications. There is nothing in tbe 
origin of new characters which can be referred to adaptation or sexual 
selection in the Darwinian sense.” Nor will Eimer allow that a more 
than probable explanation of progressive variations can be found in the 
“ principle of utility,” still less in “ fortuitous variation of the germ- 
plasma.” Varieties and species represent forms which have remained 
(in “ Genepistasis ”) at definite stages of a consecutive progress. The 
four groups have a common starting-point, and the two Ajax groups also 
spring from one root. 
Ventral Glands of Caterpillars.'^ — Dr. C. Schaffer distinguishes 
four kinds of glandular organs in caterpillars. In Vanessa lo the 
ventral gland is very short and undivided ; the wall of the tube has 
everywhere the same lattice-like appearance. In Plusia gamma the tube 
is longer than in Vanessa, but is still undivided; an efferent portion 
may be distinguished from the secreting ; when in a state of repose the 
tube is twice folded. In Hyponomeuta evonymella the glandular apparatus 
consists of two portions, one of which is distinguished by a peculiar 
plasmatic structure and an investment of a setigerous cuticle. In Harpyia 
vinula the secretory median pouch has, near its opening, on either side 
two lateral lobed appendages, from the walls of which rather long setas 
project into the lumen. The median pouch is not tubular in form. 
Alimentary Canal of Lamellicorns.t— Dr. P. Mingazzini continues J 
his account of the alimentary canal of phytophagous Lamellicorns, 
dealing now with the adult insects. Eepresentatives of six genera 
{Oryctes nasicornis, Phyllognathus silenus, &c.) were studied. The 
oesophagus of Oryctes is described at length, with its internal chitinous 
cuticle, a stratum of matrix cells, a layer of large salivary cells, a slight 
layer of connective tissue supporting the secretory cells, and finally 
muscular fibres. As a second type Mingazzini describes the fore-gut of 
Anoxia australis, which is more primitive, there being no marked difference 
between matrix cells and salivary cells. The mid-gut is very uniform 
throughout its course and throughout the series. Internally the epi- 
* Zool. Anzeig., xiii. (1890) pp. 9-11. 
t MT. Zool. Stat. Neapel, ix. (1889) pp. 26G-30I (3 pis.). 
X This Journal, ante, p. 30. 
