294 The- American Naturalist. [March, 
propositions in turn, and, in their concluding summary, state: ‘“ We 
have found that the weak point in Mr. Wallace’s argument was in the 
small amount of evidence that he was able to offer in support of each 
_ of the three propositions, so that the successive steps in the argument 
grew weaker and weaker. Indeed, it seemed to us that although many 
of his arguments were strikingly ingenious, they all appeared to rest 
on very slender evidence, or to admit of another interpretation.” The 
mechanical execution of this brochure, like that of its predecessors, 
is altogether admirable, and several excellent figures by Mr. J. H. 
Emerton add to the interest of the text. 
Oviposition of Dectes spinosus.*—Late in the forenoon of the 
rath of last July I came upon a female Dectes spinosus in the act of 
depositing an egg in the stem of horseweed (Amérosia trifida). When 
discovered she had gnawed away the outer fibres of the stem over a 
small area, and was standing head downward attempting to insert her 
Ovipositor into the stalk. After three trials she succeeded, and the : 
instrument was inserted to its base. About a minute later the posterior 
portion of the abdomen began to contract and expand, and in less 
than a minute an egg was placed in the stalk, The 
beetle then withdrew the ovipositor, and walked 
rapidly to the top of the plant. 
The egg was deposited obliquely in the pith on. 
the opposite side of the stem from which the beetle 
stood. The place of oviposition was about two-thirds 
of the way from the bottom to the top. The egg is 
2mm. long by 0.3 mm. wide; elongate oval, slightly 
curved, and of a pale yellow color. It is represented, magnified, at 4 
of the accompanying figure, while J represents, nearly natural size, 
a section of the Ambrosia stem with the place of oviposition on its 
side—C. M. WEED. 
a 
Species of Hymenoptera.—The thirty-seventh fascicle of M. 
Ed. André’s Species des Hymenoptera d’Europe et d’ Algerie has lately 
been issued. It completes the first volume of the Braconide, by Rev. 
T. A. Marshall, and adds about twenty pages to the volume on the 
Sphegidze, by M. André, who states that the work on this last-named : 
family is now suspended on account of his inability to use his eye ie 
microscopic work,—an embarrassment which his entomological brethren 
will join us in hoping may be speedily terminated.4 Four excellent 
* Read before the Entomological Club, A. A. A. S., August, 1890. 
4 Since this was written informati received of the death of M. André. 
