134 REPORT— 1870. 



spontaneous generation still insist that their hypothesis has not been refuted, and 

 that, assuming my observations to be correct, their view of the case has not been 

 fiilly disproved, I am not prepared to deny this ; but, on the other hand, I must be 

 permitted to retort that their experiments have only proved, so far, their inability, 

 notwithstanding- all their precautions, to exclude invisible germs from their infu- 

 sions. As to the mysterious appearance of these microscopical types on their solu- 

 tion ill vacuo, what is it compared with the presence of some of the internal para- 

 sites of man and the lower animals ? and who would have credited twenty years 

 since the story of the wanderings and metamorphoses which those forms undergo 

 before they find their way into the final habitat designed for them by nature ? 

 There is, however, very little chance of the controversy coming to an end at present. 

 It is fascinating and sensational, and so far quite in accordance with the spirit of the 

 age. Nor is it desirable that it should cease, for it is causing microscopical obser- 

 vers to direct their attention more and more to the beginnings of life and to the 

 development of these living types, which are visible only with the aid of the lens 5 

 and I know of no subject more worthy of the consideration of biologists." 



On the Scientific Value of Physical Beauty. By Feederic T. Mott, F.Ii.G.S. 



The purpose of this paper was to point out the connexion between the compara- 

 tive beauty of objects and their rank in the scale of nature ; to show that beauty is 

 not bestowed capriciously, but has always a scientific meaning ; that it is the index 

 of maturity, of climax, of perfected function, and ought to be taken into account as 

 such in every system of classification. The connexion between beauty and matu- 

 rity was illustrated by natural facts, and a theoretic reason for it was suggested. 



On various Alterations of Nutrition due to Nervous Infiuence. 

 By Dr. Brown S^quakd, F.E.S. 



On Apparent Transmission of Abnormal Conditions due to Accidental Causes. 

 By Dr. Brown S^qttabd, F.B.S. 



Contribution to the Migration Theory. By Dr, Caton. 



This paper contained the results of a series of experiments on the phenomena of 

 inflammation as seen in the transparent membranes of fishes and batrachians, 

 chiefly in reference to the migration of blood-cells from the vessels, described by 

 Addis'on and Waller, and more recently by Professor Cohnheim. 



In the experiments on the frog the migration of colourless corpuscles was seen 

 to take place from the vessels of the mesentery, though not in every instance. In 

 the fish, notwithstanding close observation, the escape of blood-cells was never 

 seen. Pus-cells were apparently formed in the tissues during acute inflammation. 

 It was observed that venous congestion did not occm- to the same extent as in 

 bati-achians and mammals, — possibly accounted for by the venous character of the 

 heart in the fish. In the tadpole migration was seen to take place with the greatest 

 activity whenever any considerable congestion occun-ed. In fishes and batrachians 

 alike it was found that yeneral fever caused the deposit of white blood-cells along 

 the walls of vessels ; and if, as in bati'achiaus, great congestion subsequently oc- 

 curred, the cells in contact witli the wall were seen to migrate, the more readilj' if 

 the wall of the vessel were thin and delicate, as in the tadpole. 



On the whole it seemed probable that congestion was the main cause of cell- 

 migration, and that the question whether red or white cells escaped depended 

 merely on the one or the other being in contact with the wall of the congested 

 vessel. Pus-cells appeared not to originate entirely from migrating blood-cor- 

 puscles ; indeed it seemed possible that the two had no connexion with one another, 

 and were mwely accidentally associated : for in these experiments pus-cells had been 



