378 Heart Movements QrapJdcally Displayed. 



HEART MOVEMENTS GRAPHICALLY DISPLAYED. 



BY M. MARCY. 



Gomptes JRsndus, No. 19 for this year, contains a paper by 

 M. Marcy detailing some carious investigations made with an 

 instrument which makes a mark on paper each time it receives 

 a shock from the movement of the heart of any animal against 

 whose chest it is placed. In man the resulting diagram exhibits 

 a number of pointed conical elevations, with recurring irregu- 

 larities in the ascending and descending lines. The irregu- 

 larities in these figures mark the motions belonging to the 

 contraction of the auricles, the contraction of the ventricles, 

 and the movements of the valves. 



Quite a different form is drawn when the instrument is 

 applied to the land tortoise (Testudo Europea) . The ascending 

 line is simpler. First a sloping line indicates the contraction 

 of the auricle, then the line ascends nearly vertically to a con- 

 siderable height to mark the contraction of the ventricle, 

 which, as it gradually subsides, makes a gently descending line 

 longer than the corresponding part of the ascending one. 

 This repeated in succession gives a pattern in which what we 

 may call broad tablelands alternate with deep, open valleys. 

 The heart of the frog impresses upon the instrument a tre- 

 mulous series of rounded, zig-zag lines. 



M. Marcy tried several fishes, amongst them a ray (Baia 

 alba), and the pattern yielded was in appearance between that 

 of man and that of the frog. 



Crabs, lobsters, etc., afforded a very curious diagram. 

 M. Marcy says, " In these creatures, by reason of the absence 

 of an auricle, we find a single very powerful contraction, that 

 of the ventricle.'''' The figure consists of a repetition of a 

 short horizontal line, then of a long one ascending almost at 

 right angles, then turning over, and descending as abruptly. 



The great pecten or scallop afforded a regular figure, con- 

 sisting of a zig-zag of long descending and short ascending 

 lines, sloping from left to right. The force and duration of the 

 contractions being much less than in the case of the crab, as 

 might be expected from the lower position of the animal. 



