Fig. 226.

The male urino-genital organs.

Ao Aorta.
Cl Cloaca.
Cv Inferior vena cava.
FK Fat-body.
N Kidney.
S, S1 Openings of ureters.
T Testis.
Ur Ureter.
Vr Renal veins.
Appearance of ureters on the ventral surfaces of kidneys.

Fig. 227.

Two preparations from the fat-body of Rana esculenta80.—G. H.

I. Section of fat-body, stained with borax-carmine (Hartnack, Oc. I, Syst. 7).
b Fat-cells.
c Adenoid tissue.
II. Three lobes of fat-body of Rana esculenta; coarsely injected (Hartnack, Oc. I, Syst. 3).
Arteries striped. Veins shaded.

b. [Minute structure. Each organ is completely surrounded by peritoneum, under which is a very fine layer of connective-tissue. The interior of the organ (Fig. 227 I) consists of large fat-cells with small patches of adenoid tissue interspersed. The organs are extremely vascular; each lobe has a main artery which gives off lateral branches: each of these immediately divides to form two vessels, which run in opposite directions and almost parallel with the main stem; the vessels then break up into a fine network of capillaries.]