152 EEPORT— 1872. 



The Concurrent Contemporaneoiis Progress of lienovat'wn and Waste in Ani- 

 mated Frames, and the extent to ivhich sucli Ojierat'wns arc controUahh hij 

 Artijicicd Means. By Geoege Habkis, F.>S.A., Vice-Fresident of the 

 Anthrojwioe/iccd Institute, 



The -writer, after throwing out a suggestion as to xshat a perfect system of 

 pathology might be expected to comprehend in a precise and complete knowledge 

 of the cause of each disease, and also the counteracting remedy to he applied for 

 its cure, proceeded to remark that corresponding questions arose with regard to 

 renovation and waste, as to whether the causes which affect them arc capahle of 

 control, although we are unacquainted with many of them, or whether they are 

 such as to be entirely beyond control. He adverted to the ascertained fixct of the 

 progress of renovation and waste in all animated frames, as also to the circumstance 

 that certain of these operations were known to he controllable. He analyzed the 

 principle of waste and decay in diti'erent bodies, both substantial and liquid, and 

 observed that the fact of bodies being animated did not exempt them from the 

 laws of nature. Extraordinary longevity had been attributed to certain wild 

 animals ; and it was remarkable tluit they were seldom found in a slate of de- 

 crepitude from old age. Savages derived from observation of wild animals the 

 medicinal properties of many plants and springs. Ossification of the bones and 

 deterioration of the blood had ueen considered bj' Buffon* and Smellef to be the 

 main causes of waste and decay in animated frames. The opinions of Galen, Willis, 

 Hunter, and other authorities, ancient and recejit, were cited. The writer then 

 proceeded to contend that, as the causes both of renovation and waste in certain 

 bodies are ascertained and are subject to control, these causes may be both ascer- 

 tained and subjected to control in many other cases also, if not universally, and 

 in frames which are animate as well as those which are inanimate. If you can 

 retard waste of the same natm-e with ossification, you can retard ossification also ; 

 and if you can retard ossification to a limited degree, according to our present 

 limited means and knowledge, when that means and knowledge hecome more ex- 

 tended, your power to control waste must necessarily be to a corresponding degree 

 extended as well. So also as regards the condition of the blood, and our control 

 over that condition. As science advances these causes may be better understood, and 

 the properties of various substances to control them at length perfectlj' ascertained. 

 He recommended experiments of various kinds as to the nature of substances and 

 their effect on bodies, animate as well as inanimate, and with regard to animals and 

 plants as well as man, as essential to solve this great problem satisfactorily. 



On the Mechanism of the Change of Colour in Fishes and Crustacea. 



By M. G. POTTCHET. 



As is already well known, the change of colour is due to the change in size of 

 contractile coloured cells placed in the skin. These are under the influence of 

 nerves. The author found that the particular neiTCS controlling them (in the 

 turbot) were nerves of the sympathetic. By cutting the nerve supplying a par- 

 ticular area of the skin, he had been enabled to retain that area unchanged in 

 colour, whilst the rest changed according as the fish found itself on a light or a dark 

 surface. That the eye is the means hy which the change in its conditions is com- 

 municated to the fish or crustacean, and that then a reflex action takes place, acting- 

 through the sympathetic nerves on the colour-cells of chromatophors, is proved by 

 the fact that when the animal experimented on is blinded, no further change of colour 

 occurs when it is removed from light to dark or dark to light surroundings. 



On the Mechanism of Muscular Contraction. By Dr. Eabclifpe, F.li.S. 



* Histoire Naturelle do rHomme. t Philosophy of Natural History, p. 50;.'. 



