218 THE CAT. [CHAP. vn. 



sanguineous system. It is not so because the peritoneal cavity 

 communicates (in the female cat) directly with the exterior by means 

 of the Fallopian tubes, while the sanguineous system only commu- 

 nicates with it indirectly through the opening into it of certain 

 lymphatic vessels. The mode in which lymphatic vessels ab- 

 solutely commence is a matter not yet satisfactorily ascertained, 

 but it seems they open at their minute extremities into mere vacuities 

 in the ultimate parenchyma of the body. Thus the whole lymphatic 

 system may be regarded as an enormously and most complexly 

 ramifying body cavity, the ramifications of which have all acquired 

 a lining membrane, save the most ultimate ones, from which ultimate 

 terminations the lymphatic vessels, therefore, seem to take their 

 origin. 



The various lymphatic vessels ultimately gather themselves 

 together from all parts of the body into one or other of two 

 longitudinal vessels, which are named the right and left lymphatic 

 ducts, and which are very unequal in size. 



That of the right side receives only the lymphatics of the head 

 and the fore-limb of its own side and from the same side of the 

 chest. That of the left side receives not only the lymphatics of the 

 head, arm and part of the chest of its own side, but also those 

 of both the hinder limbs and all the lacteals. It is distinguished 

 by a distinct name, the thoracic duct, but it and the right lymphatic 

 duct, respectively open into the subclavian vein of its own side, just 

 where it receives the accession of the jugular vein. 



The THORACIC DUCT advances along the ventral side of the spinal 

 column from a somewhat dilated part called the receptacuhim chyli, 

 which lies on the right side of and rather dorsally to the aorta. 

 The duct passes forwards, inclining to the left, to the root of the 

 neck, where it terminates, as before stated. 



LYMPHATIC GLANDS. There is a considerable cervical gland, about 

 the size of a very small bean, just behind the external jugular vein 

 at the level of the clavicle. 



Other lymphatic glands lie near the axilla, a group of three or 

 four being covered by the latissimus dorsi muscle near its insertion. 

 Others are situated more deeply in the axilla itself. 



A few lymphatic glands lie in the thigh just beneath the skin 

 at about half an inch from the pubic symphysis. 



Yet other lymphatic glands are to be found, besides various blood- 

 vessels and viscera. 



A large gland lies at about the middle of the trachea on its ventral 

 aspect, immediately beneath the sterno-thyroid muscle, and a smaller 

 one lies more anteriorly and superiorly near the angle of the 

 mandible. 



Certain lymphatic glands, placed in the mesentery, are known as 

 mesentenc glands. The lacteals collect together and traverse them 

 on their way to the larger lymphatic trunks. Most of the mesen- 

 teric glands are aggregated together into an elongated mass, which 



