TRANSACTIONS OF SECTION t 765 



ftftinity for water, and it is suggested that they are therefore' able td penetrate 

 the differential septa of the cell and disturb the osmotic conditions in the cell. 

 Equilibrium is upset and hydrolysis takes place, the hydrolytic enzymes become 

 functional, and a general degradation sets in. One outward manifestation of the 

 degradation is the blackening generally attributed to oxidative changes. Another 

 16 the hydrolysis of glucoside present which, in the case of the cherry laurel leaf, 

 can be observed by detecting the hydrogen cyanide formed. A third is the great 

 increase produced in the amount of reducing sugar present in the leaf. 



(v) By D. Thoday. 



A small dose of chloroform produces a temporary increase in both the 

 intake of oxygen and the evolution of CO,. A large dose is immediately or 

 ultimately fatal, and depresses the evolution of C0 2 at once. At the same time 

 in Tropceohim the intake of 0, is still more depressed, but in HeliantJnts and 

 cherry laurel, with the darkening of the leaf there is a greatly increased intake 

 of oxygen. The oxidation of tannins thus indicated, together with the hydrolysis 

 of \he cyanogenetic glucoside of cherry laurel, are made possible by an increase 

 of permeability, which partially upsets the organisation of the cells, but does not 

 immediately produce death. A similar but smaller increase of permeability may 

 account for the stimulation produced by smaller doses. 



TUESDAY, SEPTEMBER 6. 



The following Papers were read :— 



1. The Origin of the Inorganic Composition of the Blood Plasma. 

 By Professor A. B. Macallum, F.E.S. 



Analyses of inorganic composition of the blood serum in the dogfish (Acanthias 

 vulgaris), the cod (Gadus callarias), and the pollock (PollacJiius virens) have given 

 results which show that the ratios of the potassium, calcium, and magnesium to the 

 sodium are on the whole those which obtain in the blood of mammals as deter- 

 mined in Abderhalden's and Bunge's analyses. These with those of the sea water 

 are ;— 



Dogfish 



Pollock 



Cod 



Mammal (average) 



Ocean 



The amount of potassium in the blood serum of the cod as shown is high, but 

 the excess is probably due to some laking of the red corpuscles, as, in spite of 

 the care taken in the preparation of it, the serum was slightly tinged with 

 htemoglobin. Variations in the calcium are due to the different amounts absorbed 

 and retained by the fibrin in its formation and subsequent shrinkage, but these 

 are not marked. The only difference of note is in the magnesium, which in the 

 dogfish is three times what it is in the mammal, but only one-fifth what it is in 

 sea water, while in the cod and pollock it is midway in amount between the ratios 

 found in the mammal and the dogfish. 



These ratios seem to indicate that they are slight modifications of the ratios 

 which prevailed in the blood serum of the ancestors of vertebrates. The high 

 proportion of magnesium in the dogfish, the cod, and pollock may be explained 

 as due to the action of the sea water, which is rich in this element, for 

 Elasmobranchs have always been oceanic, i.e., since their origin in the Silurian 

 at the latest, and the Gadidte (cod and pollock) have been resident in the ocean 

 since the origin of Teleosts from a Ganoid form in the Cretaceous. This long 

 association with the sea has given 1 77 per cent, of total salts in the dogfish and 



1010. 3 d 



