824 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The first difficulty which is met with by a worker on this subject is 
that the meaning of a protective peculiarity can be determined only when 
the animal is seen in its natural home ; the faithfulness, moreover, of a 
protective resemblance is much less striking when the animal is seen in 
the cabinet. For the details of this interesting essay we must refer the 
reader to the paper itself. 
Sexual Selection in Attidae."^ — Mr. G. W. and Mrs. E. G. Peckham 
give an account of their observations on sexual selection in Spiders of the 
family Attidac. However satisfactory Mr. Wallace’s explanations may be 
when applied to birds and butterflies, they fail when applied to spiders ; 
his theory would only partially explain the following facts. Among 
Attidae males are more brilliant than females, young males nearly always 
resemble adult females, the males, when they dilFer from the females, 
depart from the general colouring of the group, and females, when they 
depart from the colouring of the group, approach the colouring of the 
males. Mr. Wallace’s assumption that the male animal is constitutionally 
more active than the female is not true of spiders. On the contrary, it 
is the female that is the more active and pugnacious ; in neither sex is 
there any relation between development of colour and activity ; when 
the male is distinguished by brighter colours and ornamental appendages 
these adornments are not only so placed as to be in full view of the 
female during courtship, but the attitudes and antics of the male are at 
that time such as to display them to the fullest possible extent. 
New Parasite of Lamellibranchs.f — Herr F. Koenike has a pre- 
liminary notice of a new parasite of Anodonta and TJnio which he calls 
Atax aculeatus. It appears to have been seen by Claparede in its larval 
stage, but the author has been fortunate enough to obtain the adults of 
both sexes. 
Teutonia. J — Herr F. Koenike has published a detailed account of 
this new Hydrachnid from Gelnhausen in Hesse, to the preliminary 
notice of which we have already called attention ; § only one pair of this 
interesting intermediate form seems to have as yet been found. 
Pentastomum.|| — Signor C. Parona describes Pentastomum Crociduree 
sp. n. from the peritoneum of Crocidura fuliginosa, an insect-eating 
mammal of Burmah ; the body is 10 *5 mm. long, and 1 mm. broad. It 
has sixty-two rings, on which are numerous dermal pores arranged in 
transverse rows. Pentastomum gracile Diesing is reported as being 
found in the body-cavity of Macrodon trahira. A bibliography of 
Pentastomum completes the memoir. 
e. Crustacea. 
Excretory Apparatus of Crayfish.il — M. P. Marchal gives a 
fresh account of the “ green-gland ” of the Crayfish. The saccule is 
not, as some authors have stated, a simple sac traversed irregularly by 
* Occasional Papers of the Natur. Hist. Soc. of Wisconsin, i. (1889) pp. 3-60 
(3 pis ) t Zool. Anzeig., xiii. (1890) pp. 138-40. 
X Arch. f. Naturg., Ivi. (1S90) pp. 75-80 (1 pi.). § This Journal, 1889, p. 509. 
II Aniial. Mus. Civic. dTstor. Nat. Genova, xxix. (1889-90) pp. 68-78 (1 pi.). See 
Centralbl. f. Bakteriol. u. Parasitenk., vi. (1890) p. 480. 
H Comptes Rendus, cx. (1890) pp. 251-3. 
