Figure VI. g.end., is geminating endothelium; the cells divide and apparently drop off to become white corpuscles in the lymph current. sq.end., squamous endothelium from the mesentery. sq.ep., squamous epithelium (from the mucous membrane within the cheek). st., are opening (stomata) communicating between the lymphatics in the mesentery and the peritoneal (coelomic) space. Figure VII. Ciliated epithelium from the roof of the frog's mouth. Figure VIII. Forms of glands.-- g.ep., is a gastric gland from the stomach; trs., below, is cross section. This is one of the simplest types of gland. s.g., a sweat gland, is also a simple tube, but convoluted below. r.g., is a racemose gland, such as the pancreas, Brunner's or the salivary glands. The kidney, we shall see later, is simply an aggregate of branching tubuli (Sheet 7). Figure IX. A duodenal villus.-- lac., the lacteal. v., the vein. Figure X.a. Diagram of liver structure.-- b.d., the inter-lobular bile duct. h.a., the hepatic artery, bringing blood to oxygenate and nourish the liver tissue, and similarly distributed. h.v., the hepatic vein taking blood from the liver to the heart, its twigs commencing in the lobuli (intra-lobular). lb. lb., lobuli. p.v., the portal vein bringing blood, from which substances are to be elaborated, into the liver, and breaking up between the lobuli (inter-lobular). Figure X.b. A diagram of the appearance of an injected liver lobule as seen in section under the microscope. {Illustration: Diagram Sheet 3.} Sheet 4 Histological Diagrams, 2. Figure XI. A blood capillary. White corpuscles are migrating through the walls into the tissues (compare Section 66). Figure XII. Hyaline cartilage (Section 64). Figure XIII. c.c., connective tissue corpuscle. w.i.f., white inelastic fibres. y.e.f., yellow elastic fibres. Figure XIV. Botryoidal tissue (Section 66). Figure XV. Development of a fat drop.-- f.d., fat drop, in a connective tissue corpuscle; c.c., in the formation of adipose tissue (Section 67). Figure XVI. Diagrammic cross section of a long bone.-- b.c., bone corpuscle in a lacuna. H.v., Haversian vessel (in the Haversian canal) surrounded by concentric lamellae of bone, c.l., and together with these and zones of bone corpuscles, called a Haversian system. i.l., inner lamellae. m.c., medullary canal full of yellow marrow. o.l., outer lamellae. p.o., periosteum. Figure XVII. To illustrate bone development (Section 71). Figure XVIII. Dentition of rabbit, incisors 2/1, canine 0/0, premolar 3/2, molar 3/3. {Illustration: Diagram Sheet 4.} Sheet 5. Diagram of the Rabbit's Bones. To be compared with the real things.