( 230 ) 



corpus genieulatum mediale, the more remarkable because therein 

 many cells are lost, only there, were the bracchium conjunctivum 

 from the ganglion quadrigeminum posticum enters in the corpus 

 mediale. At the same time the atrophy in the left bracchium conjunc- 

 tivum is more important than that on the right side. The preponderance 

 of the atrophy in the left bracchium, in accordance with the atrophy 

 of the lateral lemniscus described before, is considered by the speaker 

 as being occasioned by the encephalitic process. This focus was not 

 situated (or only to a very small extent) in the temporal radiation 

 of the corona radiata. It is not followed by an intense atrophy in 

 the homolateral corpus genieulatum mediale, and therefore, cannot 

 in itself be held answerable for the auditory defect of the animal. 

 This deaf-bom white cal with the blue eyes consequently may not 

 be considered to be a deaf variety of the genus cat. It is a patlio- 

 logical product. An encephalitis, probably during the intra-uterine 

 life, has destroyed a part of the left hemisphere (not the so-called 

 auditory radiation) and occasioned a hydrocephalus in tern us. Its pression 

 became a danger to all the systems at the surface of the ventricles. 

 More especially those systems were endangered that were threatened 

 from both sides by compression according to their position on the 

 border of the recessus lateralis. The stria acustica was destroyed in 

 that way. 



Botany. — "On the investigations of Mr. A. H. Blaauw on the 

 relation between the intensity of light and the length of illu- 

 mination in the phototropic curvatures in seedlings of Avena 

 sativar By Prof. F. A. F. C. Went. 



Some years ago Wiesner *) attempted to ascertain, what is the 

 minimum intensity of light to which various plants still react photo- 

 tropically. He found, for instance, that with the epicotyl of Piswn 

 sativum and the hypocotyl of Lepidiwn sativum the limit of sensitive- 

 ness is not yet reached at 0.054 normal candle power. (Wiesner 

 expresses it in a unit which is equal to 6.5 Spermaceti candles). For 

 the epicotyl of Phaseolus multiflorus the limit is exactly at 0.054 

 normal candle power. While in this case, the author does not 

 mention the duration of the experiments, he states for the epicotyl of 



!) J. Wiesner. Die heliotropischen Erscheinungen im Pflanzenreiche. Wien 1878. 

 p. 178—180. 



