3. Die höheren Lebenseinheiten. 629 



3. Die höheren Lebenseinheiten. 



(Siehe auch Nr. 1743, 1744, 1764, 1770, 1773, 1784.) 



1748) Tiegel, M. (Dortmunder Louisenhospital), Experimentelle Unter- 

 suchungen über den physiologischen Unterschied zwischen Unter- 

 und Überdruckverfahren. 



(Beitr. z. klin. Chir. 76,1. p. 160—186. 1911.) 



Verf. stellt die Ergebnisse seiner experimentellen Arbeit in folgenden 

 Sätzen zusammen: 1. Das Tierexperiment zeigt bei dem Überdruckverfahren 

 konstant eine Erhöhung des Druckes in den endothorakalen Venen. Bei dem 

 Unterdruckverfahren bleibt dagegen der physiologische negative Druck in den 

 Venen erhalten, ja er wird bei stärkerem Minusdruck (10 — 15 cm) sogar ein 

 wenig erniedrigt. 2. Der Druck in der Lungenarterie steigt bei dem Über- 

 druckverfahren über den beim Lungenkollaps bestehenden hinaus; bei dem 

 Unterdruckverfahren sinkt er unter ihn herunter. Es ist dies ein Zeichen, 

 daß die Passage des Blutstromes durch die Lunge bei der Überdruckatmung 

 erschwert, bei der Unterdruckatmung erleichtert ist. 3. Der Druck in den 

 peripheren Arterien wird durch das Unterdruckverfahren ein wenig erniedrigt, 

 offenbar weil durch Erweiterung von peripheren Kapillargebieten der Gefäß- 

 widerstand verringert wird. Die geringen Druckwerte, wie sie praktisch bei 

 dem Überdruckverfahren zur Anwendung gelangen, sind ohne wesentlichen 

 Einfluß auf den arteriellen Blutdruck. Paul Wagner (Leipzig). 



1749) Arnisby, H. P. and J. A. Fries, The Influence of Type and of 

 Age upon the Utilization of Feed by Cattle. 



(U. S. Dept. Agr. Bur. Anim. Ind. Bulletin 128. p. 1—245. 1911.) 

 This very intensive and thorough study makes a detailed comparison of 

 the metabolism of beef cattle of different types. The plan of the investigation 

 was as follows: 



„Two steer calves were selected as the subjects of investigation. One of 

 these was a purebred Aberdeen-Angus of typical beef form, while the 

 other was a „scrub" containing considerable Jersey blood and possessing the 

 dairy rather than the beef form. These animals were about 8'/ 2 and 11 months 

 old, respectively, at the beginning of the investigation in October, 1904, and 

 were under nearly continuous Observation for over 2 l l 2 years. During this 

 time, with the exception of certain of the periods in which the balance of 

 matter and energy was determined by means of the respiration calorimeter, 

 they were fed an ordinary growing ration, and while maintained in a thrifty 

 condition were at no time fattened. The feeding stuffs used were of the same 

 kind for both animals in all the periods, and the different grains used were 

 mixed throughout in the same proportions for each steer. The live weights 

 of the animals were taken at least once weekly, as well as on three con- 

 secutive days at the end of each month, and they were systematically measured 

 and photographed every three months. At intervals during this time the 

 digestibility of the total ration and the nitrogen balance were determined for 

 each animal." 



„During each of the three winters covered by the investigation four ex- 

 periments were made on each animal by means of the respiration calorimeter 

 in order to determine the percentage availability of the energy of the feeds 

 consumed. During the first winter, that of 1904 — 1905, the feeding stuffs 

 used differed from those employed during the ordinary feeding. In the 

 succeeding two winters the grain feeds used were the same, only the amounts 



