524 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1915. 



of work which would yield profitable results. To this the success of 

 the school was mainly due. Its popularity was increased by the 

 method of procedure adopted by Ludwig. This has been described 

 by Sir T. Lauder Brunton, who was with Ludwig in 1869-70. The 

 experiments were carried out by Ludwig with the pupil as assistant ; 

 Ludwig wrote the paper and then published it, occasionally as a con- 

 joint work, but more usually in the name of his pupil. As I have 

 heard from Gaskell, the method was the same in his time. The work 

 given him was a continuation of that on the innervation of skeletal 

 muscle already begun in the laboratory. This led him by a series of 

 steps, which were perfectly logical but impossible to foresee, from 

 point to point of scientific inquiry up to his theory of the origin of 

 vertebrates. 



Soon after his return to England in 1875, Gaskell married Miss 

 Catherine Sharpe Parker, a daughter of Mr. E.. A. Parker, of the firm 

 of Messrs. Sharpe, Parker & Co., solicitors, by whom he had one son, 

 Dr. J. F. Gaskell, and four daughters, two of whom survive him. He 

 settled in Grantchester, about a mile and a half from Cambridge, and 

 in the Cambridge Physiological Laboratory he carried further the 

 investigation on the innervation of the blood vessels of striated 

 muscle. He found (1877), amongst other facts, that stimulation of 

 the nerve supplying the mylohyoid muscle of the frog caused con- 

 siderable and constant dilatation of the blood vessels, although con- 

 traction of the muscle itself was prevented b}^ curare. This was the 

 most decisive instance known at the time of such action in a purely 

 muscular structure. It did not, however, settle the question of the 

 occurrence of vaso-dilator fibers in the nerves of skeletal muscle, the 

 discussion of which was carried on by Heidenhain and others. 



From the behavior of the arteries under nervous stimulation he 

 passed to the investigation of the behavior of the small arteries and of 

 the heart with varying reaction of the blood, and, finding that a 

 small addition of alkali increased the tone of both, and that a small 

 addition of acid decreased it, he suggested that, besides the nervous 

 control of the circulation, there was also a chemical control in each 

 organ and tissue by the products set free in activity, so that, for ex- 

 ample, the contraction of the muscle by setting free acid led to an in- 

 creased flow of blood through it. The suggestion was not entirely 

 new, but it was wider in range than any of its kind previously made 

 and rested on more solid facts. This work directed his attention to 

 the heart, and for the next four or five years he devoted his time to 

 the questions of the innervation of the heart, and the cause of the 

 heart beat. With these questions others were busily engaged, notably 

 Engelmann and Heidenhain. 



In the early seventies it was universally held that the beat of the 

 heart was due to the nerve cells present in it, and that it was initiated 



