452 3. Die höheren Lebenseinheiten. 



supplied is not necessarily proportional to the bloodsupply, since in these ani- 

 mals there is a mixture of arterial and venous blood. But in birds and mam- 

 mals the arterial blood is saturated with oxygen, and hence the amount of 

 oxygen is proportional to the supply of blood. In the foetus this is not the 

 case, since the Ductus Botalli remains open, and in some cases at least the 

 young are not able to regulate the temperature for some time after birth. 

 The author has observed or collected from the literature the average C0 2 Out- 

 put (measuring oxygen used), the heart-weight in percentage of body-weight, 

 and the frequency of beat per minute in a nuraber of birds and mamraals, 

 and finds that the C0 2 Output decreases regularly with increase of weight of 

 the animal, and that as long as the relative heart-weight is the same, the 

 pulse-rate varies directly with the C0 2 Output. With constant C0 2 Output 

 the pulse-rate and heart-weight have a reciprocal relation. In this way, know- 

 ing the three measures for one bird or mammal, the pulse-rate of another 

 can be predicted with accuracy if its C0 2 output and relative heart-weight 

 are known. The method of determining pulse-rates in small animals by the 

 capillary electrometer is described; since in some cases it amounts to 1000 

 per minute direct Observation is precluded. 



Since the regulation of the oxygen supply depends both on the relative 

 size of the heart and on the rate of beat, it is interesting to note that in 

 animals which do much work, the heart is relatively larger and the beat 

 slower, for example, the rabbit has a small heart and rapid beat, the hare 

 a large heart and slower beat when at rest, but by increasing the beat it can 

 enormously increase the oxygen-supply when running long distances. The race- 

 horse has a heart relatively nearly twice as large as an ordinary horse. In 

 conclusion, evidence is given that increase in rapidity of beat is due to im- 

 pulses travelling to the heart by the vagus, which are produced almost instanta- 

 neously by even small muscular action. Other factors may be concerned in the 

 great acceleration following severe exercise, but the almost instantaneous effect 

 of slight muscular action can only be interpreted as a direct nervous Stimulus. 



Doncaster (Cambridge). 



918) Pearson, K., On a new method of determining correlation, when 

 one variable is given by alternative and the other by multiple 

 categories. 



(Biometrika 7,3. p. 248—257. 1910.) 

 Mathematical. Illustrated by examples of correlation between Handwriting 

 and Eye-colour, Alcoholism and Health of Children, Vaccination and Severity 

 of attack etc. Doncaster (Cambridge). 



919) Leon, A. und. M. Flack (Physiol. Inst. Bern), Nachweis der Wir- 

 kung eines inneren Sekrets der Schilddrüse und die Bildung 

 desselben unter dem Einfluß der Nerven. 



(Zentralbl. f. Physiol. 24,6. p. 211-213. 1910.) 

 Jedesmal, wenn die peripheren Enden der durchschnittenen Nervi laryngei 

 gereizt wurden, war die Erregbarkeit des N. depressor erhöht, die Blutdruck- 

 senkung also stärker als ohne Laryngeusreizung. Es müssen daher die 

 N. laryngei die Bildung eines hierzu geeigneten Stoffes in der Schilddrüse 

 veranlassen und die sekretorischen Nerven dieser Drüse sein. Während einer 

 Reizung der N. laryngei und gleichzeitiger Unterbindung der N. depressores 

 bewirkt ferner auch die gleiche Adrenalindosis größere Blutdruck Steigerung 

 als ohne die bezeichnete Reizung, wodurch Faltas Annahme von der gegen- 

 seitigen Förderung der Schilddrüse und Nebenniere neu bestätigt erscheint. 



Kamm er er (Wien). 



