67 6 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Yerh. ; lulus s. str. with nine subgenera ; Pachyiulus Verh. with two 
subgenera ; Palaioiulus Yerh. with three subgenera ; and, lastly, 
Tachypodoiulus Yerh. He gives an elaborate diagnostic table of the 
genera and species. For the collector north of the Alps he notes that 
the common forms are mostly species of lulus s. str., besides which and 
the readily recognizable Blaniulus and Isobates, there are five species to 
be met with, Micropodoiulus terrestris , M. terrestris , Tachypodoiulus 
albipes , Palaioiulus sabulosus , and P. mediterraneus. 
Poison-Glands of Chilopoda.* — M. 0. Duboscq describes the struc- 
ture of the poison-glands of Scolopendra cingulata ; around the excretory 
canal, which consists of thick chitin, the glandular substance appears to 
be arranged, but the duct is morphologically superficial ; the glandular 
substance is formed of numerous tubes, with a delicate basement mem- 
brane, with small cells in a state of active proliferation ; so that each 
tube produces and contains a large quantity of poison. Among the 
tubes are numerous striated muscular fibres, and there is a well-developed 
muscular apparatus for the compression of the gland, and the expulsion 
of the poison. The structure is essentially the same in other Chilopods ; 
Gryptops , Geophilus , Lithobius, and Sciitigera have been examined. 
8, Arachnida. 
Development of Lungs of Spiders, j — Mr. O. L. Simmons finds that 
the lungs of the Spider arise as infoldings upon the posterior surface of 
the appendages of the second abdominal somite, in the same way as the 
gills of Limulus (Kingsley). They have the same growing point, and 
form lung-leaves in the same way as the gill-leaves arise. The lung- 
books of the Spider, therefore, arise at first as an external structure on 
the posterior surface of the abdominal appendages ; they sink in, with- 
out any inversion or other complications, in the way suggested as 
probable by Kingsley. 
The tracheae develope from the limbs of the third abdominal somite ; 
in their earlier stages these appendages have on their posterior surface 
a folding similar to that on the member in front. The author concludes 
from this that the lung-book condition is the primitive, and that the 
tracheae of the Arachnids are derived from it, and he advances the gene- 
ralization that the facts adduced leave “no ground for those who regard 
the 4 Tracheata ’ as a natural group of the Animal Kingdom.” 
Ccelomic Cavity of Spider.* — Mr. K. Kishinouye has investigated 
various species of Lycosa and Agalena. He finds that, in the course of 
development, the ccelomic cavities in the segments of the cheliceraj and 
pedipalps degenerate and disappear ; the greater portion of the coelomic 
cavities of the four ambulatory appendages degenerate, while the meso- 
derm cells that form their wall become gradually changed into muscles. 
The coelomic cavity of the first ambulatory appendage communicates 
with the exterior by means of a duct of ectodermic origin. The forma- 
tion of the dorsal circulatory system greatly resembles that of Limulus. 
Later on, the coelomic cavities in the cephalothorax all disappear, except 
the small portions at the outer bases of the first to third ambulatory 
* Comptes Kendus, cxix. (1894) pp. 352-4. 
t Amer. Joum. Sci., xlviii. (1894) pp. 119-28 (1 pi.). 
% Journ. Coll. Imp. Univ. Japan, vi. (1894) pp. 287-94 (1 pi.). 
