COXAL GLAND OF LIMULUS AND ARACHNIDA. 
519 
EXPLANATION OF PLATE XXXVI, 
Illustrating Mr. Gulland’s paper on “ Evidence in favour of the 
View that the Coxal Gland of Limulus and of other 
Arachnida is a Modified Nephridium.” 
Fig. 1. — Diagram of a transverse section of Limulus at the level of the 
internal opening of the coxal gland, co. gl. Coxal gland. A. Primary tube. 
m. Muscle, h.c. Hepatic caeca, ento. Entosternite. int. Intestine. H. Heart. 
p.c. Pericardium, n.c. Ventral nerve-cord. 
Fig. 2. — Diagram of the coxal gland spread out on a plane surface, ant. 
Anterior end. post. Posterior end. du. Duct or external opening, int. op. 
Internal opening, sep. Septa in the lumen of the gland. 
Fig. 3. — Dorsal view of young Limulus (the original was 12 millimetres in 
length from the anterior end to the root of the spine, 19 mm. altogether, and 
12 mm. in breadth at the level of the 4th appendage, where it was broadest), 
to show the relations of the coxal gland. I — VI. The coxae of the appendages. 
co. gl. Coxal gland, ento. Entosternite. 
Figs. 4 — 11. — Common references. A. Primary tube of coxal gland. 
B. C. D. Secondary tubes, c. gl. e. Epithelium of coxal gland, b. m. Base- 
ment membrane, m. Muscle, c. t. c. Connective-tissue corpuscles. T. Tra- 
beculae of connective tissue, b. c. Blood-corpuscles. 
Fig. 4. — To show the derivation of tube D from C, and the continuity of 
the epithelium. 
Fig. 5. — Transverse section of the coxal gland, showing the relations of 
tubes to one another, the intertubular connective tissue, and to the left 
of D, the space into which that tube is about to open. 
Fig. 6. — The next section to Fig. 5 ; the partition between D and the 
connective tissue is no longer present. 
Fig. 7. — The next section but one to Fig. 6, the intervening one being 
exceedingly like Fig. 6, was not drawn. 
Fig. 8 — The next section to Fig. 7. 
Fig. 9. — The next section to Fig 8. The connective-tissue trabecula T, 
has closed the opening of D, which becomes smaller in each succeeding 
section, and soon disappears. 
Fig. 10. — A small portion of the gland epithelium more highly magnified 
showing the radial striation of the cortical part. 
Fig. 11. — Part of a section of the coxa of the fifth limb, showing the 
duct of the coxal gland near its opening, and while it is still lineU with 
