252 THE SALAMANDER 



appearance it closely resembles a sinus in Lacerta, figured by Hoyer 

 (Anat.Anz., Bd. 73) and named by him 'Sinus thyroideus', but in Sala- 

 mandra the glands lie much deeper than the plexus and are not 

 associated with it. It therefore seems preferable to avoid this name. 

 The lateral plexuses underlie the skin right along the sides of the 

 trunk and the base of the tail. They lie mainly ventral to the sulci 

 laterales, but extend dorsalwards over the scapula and ilium. They 

 are particularly rich in the neighbourhood of the limbs. 



B. Lymphatics of the Limbs. 



These were first described by Panizza with considerable accuracy, 

 and later Hoyer and Udziela gave a more detailed account of their 

 course in the larva. There is no essential difference between the 

 fore- and hind-limbs so that a general description may serve both. 



The whole limb is covered by a subcutaneous network which may 

 be imagined as arising along the sides of the digits. At the bases of 

 the metacarpals (or metatarsals) between the digits there are small 

 lymphatic sacs which lead by short vessels into a palmar (or plantar) 

 sac covering the whole ventral surface of the hand (or foot). This 

 sac lies between the skin and the fascia of the superficial flexor 

 muscles, and is penetrated by a number of fibrous threads which 

 attach the fascia to the skin, so that the sac is broken up into a reti- 

 culum with very small meshes. It is in free communication proxi- 

 mally with the network covering the rest of the limb. In the region of 

 the elbow (or knee) this network tends to drain into a pair of vessels 

 passing along the pre-axial and post-axial sides of the proximal part 

 of the limb, which latter in turn drain into the sacs lying around the 

 shoulder and hip respectively. Small lymphatics also accompany the 

 blood-vessels within the deeper parts of the limbs and communicate 

 freely with the vessels just described. 



C. Lymphatics of the Pelvic Region and Tail (Fig. 69). 



On the ventral side of the pelvis is the sub-pelvic network above 

 described. The greater part of this may be lifted as a sheet disclosing 

 a series of three pairs of deeper sinuses, which, nevertheless, still lie 

 superficial to the muscles. They may be called, from their positions, 

 cloacal sinuses, pelvic sinuses, and inguinal sinuses respectively. 



The cloacal sinus (s.ly.cl.) differs somewhat in extent in the two 

 sexes. In both it extends as a broad sheet across the ventral surface, 

 on either side of the cloacal opening. In the female it also extends 

 dorsalwards lateral to the walls of the cloaca itself, while in the male 

 there is a lymphatic network ramifying among the tubules of the 



