464 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
refractive, colourless, homogeneous bands ; the nuclei are polyhedral, 
feebly staining bodies containing large, intensely coloured chromatin 
grauules. The epithelium of the same region of the gut consists of high 
and very delicate cylindrical cells, which widen out somewhat at their 
free ends. The nuclei are large and of an elongated oval form. 
Between the third pair of blind tubes and the enteric sacs the dorsal 
wall of the mid-gut forms a glandular area ; the peculiarity of the 
epithelial cells is that the nuclei, lying in the centre of the cell, are 
surrounded by a clear area. Just before the mid-gut passes into the 
abdomen there is developed a so-called enteric sac ; this is a gland 
made up of four parts, which may be regarded as simple, pouch-like 
evaginations of the wall of the mid-gut. In the hind-body the mid-gut 
gives rise to the so-called hepatic tubes ; these are not, as in true Spiders, 
united into a compact mass, but form a system of dichotomously branch- 
ing cylindrical tubes, not connected together with intermediate tissue ; 
these tubes fill up all the interspaces between the different organs. Their 
investing tunica serosa does not form a complete layer, but rather a loose 
mesh work, which consists of groups of cells connected with one another 
in a plexiform manner. The epithelium consists throughout of similar, 
cylindrical, high cells, and there is no division into ferment- and liver- 
cells, as in true Spiders and Crustacea. The pigment-granules contained 
in them show, however, that they must be compared with the liver-cells 
of Spiders, Crustacea, and Molluscs. 
American Spiders.* — The first volume of this valuable and interesting 
work presented evidences of original and persistent research not often 
equalled in the class of biological work it deals with, and revealed to 
a much larger area of readers than his previous academic memoirs could 
possibly have done, the great value, and frequent entire originality of 
Dr. McCook’s researches. Beyond this, the book w r as so written and illus- 
trated as to arrest many other readers than biologists studying and seek- 
ing the fullest knowledge of aranean life and habits. 
The present volume surpasses its predecessor in many respects ; it 
represents a very large amount of close personal observation, and that on 
just those points on which information is so desirable and needed. Dr. 
McCook throughout deals lightly with the anatomy and physiology of 
the group ; although he shows perfect familiarity with the latest and 
best work done on these subjects, up to the time of going to press. But 
his observations throughout are on the habits and work of the spiders. 
The chapters in this volume on “ The Courtship aud Mating of Spiders ” 
are certainly treated in a popular manner ; but manifestly this is the 
character of the entire book ; nevertheless, it nowhere obscures or even 
endangers accuracy, and in so complex and difficult a subject this is 
evidence of a high order of success. 
The illustrations given are as life-like, as to the observer of spider 
life they are singularly happy and true ; only the author’s opportunities of 
observation have been of an unusually ample nature. His observations 
on these aranean lovers, the stages of their courtship, and the fierce and 
curious quarrels of the males for the possession of the females, are not 
* McCook, H. C., D.D., ‘ American Spiders and their Spinning Work. A Natural 
History of the Orbweaving Spiders of the United States, with special regard to their 
Industry and Habits.’ Vol. ii., 479 pp., 5 pis. Published by the author. 
