ON THE EARLY PULSATIONS OF THE POSTERIOR 



LYMPH HEARTS IN CHICK EMBRYOS: THEIR 



RELATION TO THE BODY MOVEMENTS 



ELEANOR LINTON CLARK AND ELIOT R. CLARK 

 From the Anatomical Department of the Johns Hopkins University 



TWO CHARTS 



INTRODUCTION 



The lymph hearts of the chick were discovered by Budge in 

 1882. Previous to this, pulsating lymph hearts had been de- 

 scribed in adult aquatic birds and in the ostrich and cassowary, 

 by Stannius and Panizza. Budge found that lyniph hearts, 

 although absent in adult chickens, are present in the embryo 

 and function from the ninth day to the time of hatching. He 

 was able to inject these lymph hearts, from the lymphatic ves- 

 sels surrounding the allantoic arteries, in embryos of ten days 

 and over, and he describes them as two rounded sacs, situated 

 on each side, at the angle between the tail and pelvis, and super- 

 ficial to the myotomes. He studied the muscles in the wall of 

 the lymph heart by dissection of fixed preparations. Budge also 

 discovered the lymph heart in living chicks, of eight days and 

 over, and found that its pulsations did not coincide with those 

 of the blood heart. Budge concluded that, since the lymph 

 hearts make their appearance at approximately the same time 

 as the lymphatic vessels of the allantois and atrophy with the 

 disappearance of the allantois, they are intimately connected 

 with the function of that organ. 



A more extensive study of the lymph hearts of the chick was 

 published in 1900 by Sala. The lymph hearts, according to 

 Sala, in embryos of eight days, are clear almond-shaped sacs 

 situated on either side of the tail, lateral to the myotomes and 

 somewhat ventral to the caudal margin of the os ilii. After the 



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