REVIEWS. 617 
traordinary. But the great number of full-grown second-form specimens 
n every species, which are often even larger than the first-form males, 
seems to prove that they are individuals which have remained in a sexual 
stage that does not agree with their corporal development, — in short, 
that they are perhaps sterile." "This conjecture he finds supported by an 
anatomical examination. 
We quote all the author's general remarks on Dimorphism in Crustacea 
and Insects (p. 24). We have noticed in the NATURALIST, vol. iii, p. 494, 
iv, p. 55, the recent discoveries of Malmgren, Ehlers, Claparéde and oth- 
ers, regarding dimorphism in the worms, which our readers would do 
well to read in this connection. 
imorphism in other Crustacea.— Perhaps this fact of the existence in the crustacea of two 
orms, one always sterile, is not unique. In " e genera Lupa and Callinectes, there are not 
rarely females with a very narrow and acute postabdomen. siete t is very easy to separate 
from the ordinary females, with a large and cireular eset vane n. Professor L. Agassiz in- 
ino me em he decr satisfied bimaal A of 1 iving specimens, met 
wW ith A LHGILUYM v 
some other g f Brachyur 
I am indebted to Mr. Alexa andes Agassiz for the information that F. Sagen Fuer Darwin, 
MS has described two forms of the male in M hestia Darwinii and in is dubius, He re- 
arks that when found upon die shore the form of the second pair of gna pista varies from 
dint of the specimens found at: a distance pia i where D lives under mouldy leaves in loose 
earth. In ith large and those with small 
pragak are y Het; tö be detected, but in two other species, 0. tucurauna a € S tucuratinga, the 
shap the hands changes even in the full-grown 
oid Q 
sts that 4} Bunt? burrowing 
= 
pem hahit 
The Veces of two different forms of males in Cambarus is very important in the oen 
tion «o species, and the fact that these forms are n Mee by all preceding au 
may e wor 
"Dimorpham in Insects, +The Areora © of morp 
Wresting 1 di hi was known only ing the PERRE 
re H 11 4 H 
which 
a general review " vy desirable. An ee examination bos mese dimorphic ibis is 
Still wanting, only t 
The dimorphism seems to be represented in two different ways; a difference only in the 
colors (dichroic forms of Brauer), or a difference in size and shape, and mostly in the female, 
we same 
ld m m I s 
Species, and atio? nthe female. Perhaps in the ants and in the white ants— it seems more 
natural to r ange all the socially living insect, Mts the ants, bees, wasps, and white pie under 
the same] 
Dim l ally in Lepidoptera 
2 — hind etae of many Orthoptera, and in =e females of ppe gt es latter genus the 
sterile, 
og difference in the der opti of the wings. The ar ither e and well-devel- 
ped, or short, or entirely wai The n thoptera (Gryllus, Loeust lat 
bie ag T ocus) have n carefully described by Messrs. Fischer, Von ld, Lu- 
S, Brauer, and m iod Fideles ely r apterous Hemiptera, by Westw l 
the -winged Diptera by Schaum ( Lip- 
Ornithobia an 
ra). Mr. resda is mit wolar an goiat = per upon dimorphism in the genus 
a. e win ith 
whi : 
complicated neuration and different colors. There ripe even a case of morphism in some but- 
; s of j Cel 
t . according to the observation Mr. Wallace. Papilio Orm om Celebes, has 
three distinet forms of females, a n some cases inde number of female forms appear: be 
four. Dimorphism desse in different shape d size is observed in the Lepidoptera 
(Equites, ete.), in the Coleoptera, in the Lame nior, and in the Longicornia, and perhaps 
AMER. NATURALIST, VOL. IV. 78 
