218 
INSECTA. 
the last Report is of the usual American practical nature, discussing in- 
sects injurious to apple and cotton- wood, and containing also general 
* Outhnes of Entomology.' 
Leconte, J. L. Hints for the promotion of Economic Ento- 
mology in the United States. Am. Nat. vii. pp. 710-722. 
This paper, read before the Portland meeting of the American Asso- 
ciation, contains a historical review of American Entomological works, 
and many valuable suggestions for the further improvement of the prac- 
tical works now published. 
LowNE_, B. T. On the Structure of the Mouths of Insects. 
Sci. Goss. 1873, pp. 229-232, figs. 142-146. 
The commencement of an illustrated explanatory series of observa- 
tions, apparently intended for microscopists. Fig. 145, " The mandible 
of a predatory beetle," is an amalgamation of mandible, maxilla, 5-jointed 
maxillary palpus, and 3-jointed labial palpus. 
Lubbock, Sir J. On the Origin and Metamorphoses of In- 
sects. Nature, vii. pp. 446-449, 486-489, viii. pp. 31-33, 
70-73, 107-109, 143-146, 167-169, 207-209, pis. i.-vi. & 
63 figs, [also published separately, in ^' Nature Series,''^ 
sm. 8yo, 1874] . 
After a general outline of the Insecta, and a comparison of the larvae 
of various orders, the author comes to the conclusion that the form of 
the larva, whenever it departs from the hexapod Campodea type, has been 
modified by the conditions of its life ; and, accordingly, that metamor- 
phoses are either developmental or adaptive. The embryonic stage is 
compared with that of other Articulata. The ultimate conclusion is that 
the Insecta generally are descended from ancestors resembling Campodea, 
and that these have themselves arisen from others belonging to a type 
represented more or less closely by Lindia {cf. also a review by this 
author of A. S. Packard's ' Ancestry of Insects ' in Nature, viii. 
pp. 249 & 250). 
LuNGERSHAUSEN, Louis. Die Vertheidigungsmittel der Insecten- 
welt. Das Ausland, xliii. (1870), pp. 984-992. 
An interesting general account of the means of self-defence possessed 
by insects. 
Meldola, Raphael. On a certain Class of Cases of Vari- 
able Protective Colouring in Insects. P. Z. S. 1873, 
pp. 153-162. 
The author urges the adoption of Wallace's distinction between the 
terms " mimicry " and " protective resemblance," the former of which 
(the result of a ])sychical mimetic adaptation," and not a voluntary 
imitation) is to be applied only to cases in which the object simulated is 
;iuimate. 
Instances ol: protective resemblance are classified under heads : 1, con- 
