LYMPHOSIS. 



675 



r 



Lymph Heart of Python Bivit- 



tatui after Weber. Heart 

 9 lines long; 4 broad. 



*. External areoiar coat. 5. 



- 

 here > and tw veins, '2, 2. e. 



Smooth lining membrane of the 



cavity. 7. An appendix or au - 

 ' C m " 



these lymphatic hearts do not correspond with Fig. 261. 



those of the sanguiferous heart; nor do those of 

 the right and left sides occur synchronously. 

 They often alternate irregularly. Prof. E. H. 

 "Weber has described them in a larger species 

 of serpent python bivittatus; 1 and Dr. Joseph 

 J. Allison, of Philadelphia, 2 a young and zeal- 

 ous observer, who was cut off early in his ca- 

 reer, saw them in the tadpole, the frog, the 

 sauria, ophidia, and chelonia. His researches 

 led him to conclude : First. That the pulsa- 

 tions of the lymphatic organs vary in different 

 specimens (frogs and tadpoles) from 60 or less 

 to 200 per minute. Secondly. That they vary 

 in the same individual so as sometimes to be- 

 come double in frequency. Thirdly. That 

 the lymphatic pulsations bear no fixed relation 

 to those of the pulmonary heart or to respira- 

 tion, the lymphatic hearts beating on an 

 average with greater frequency. 



More recently, Professor Stannius 3 has dis- 

 covered lymphatic hearts in various birds. 



Unlike that of the heart, the action of these lymph hearts appears 

 to be dependent upon a certain limited portion of the spinal cord ; for 

 Volkmann 4 found, that by dividing the anterior or motor roots of the 

 spinal nerves connected with them, the pulsations immediately ceased. 



The course of the lymph is by no means rapid. If a lymphatic be 

 divided on a living individual, the lymph oozes slowly, and never with 

 a jet. M. Cruikshank estimated its velocity along the vessels to be 

 four inches per second or twenty feet per minute; but it is probably 

 much less. M. Collard de Martigny 5 obtained nine grains of lymph 

 in ten minutes from the thoracic duct of a rabbit, which had taken no 

 food for twenty-four hours. Having pressed out the lymph from the 

 principal lymphatic trunk of the neck, in a dog, the vessel filled again 

 in seven minutes : in a second experiment it filled in eight minutes. 

 The data for any correct evaluation of this matter are altogether in- 

 adequate, the deranging influence of all such experiments being con- 

 siderable. 



In man and living animals, the lymphatics of the limbs, head, and 

 neck rarely contain lymph; their inner surface appearing to be merely 

 lubricated by a very thin fluid. Occasionally, however, the lymph 

 stops in different parts of the vessels; distends them; and gives them 

 an appearance very like that of varicose veins, except as to colour. 

 Somrnering states, that he saw several in this condition on the top of 



1 Muller, op. citat, p. 275. 



2 American Journal of the Medical Sciences, for August, 1838. 



3 Muller's Archiv., 1843, Heft 5. 



4 Ibid., 419, Berlin, 1844; and Valentin, Lehrbuch der Physiologie des Menschen, ii. 769, 

 Braunschweig, 1844. 



5 Journal de Physiologie, torn. viii. 



