450 



as transition forms from polygonal and bladder cells to this loose, 

 cellular type of the stratum corneum are apparent. In fig. 5 the 

 stratum lucidum is shown, stained a deep red by the acid fuchsiue, 

 and may be traced as a direct continuance of the nail (n) tending to 

 show that nail and stratum lucidum are produced at the same relative 

 point of the epidermal development, both being covered by an epi- 

 trichial layer, which in the case of the nail is lost in the later months 

 of foetal life (although there are remfiins to be seen after birth); while 

 the epitrichial layer covering the stratum lucidum persists, and forms 

 the typus A of Zander. 



I am well aware that many objections may be raised to this 

 theory. It is so strikingly suggested by acid fuchsiue preparations 

 of the foetal nail, that I have ventured to allude to it, and further 

 investigations, in which I am now engaged, will, I hope, decide its 

 truth or falsity. 



As a brief summary of these results, I feel justified in affirming: 



1. That the outermost epidermal cells of young embryos form a 

 distinct, histological layer. 



2. That this layer disappears by the 6"' month over most portions 

 of the body. 



3. That in certain places, as in the region of the nail, this laytir 

 undergoes a keratosis, and forms a part of the stratum corneum. 



4. That there are good reasons for regarding this layer as homo- 

 logous with the epitrichium of animals. 



5. That the nail is a modified portion of the stratum lucidum, 

 and becomes exposed by the loss of the epitrichial layer. Whether 

 the cells overlying the stratum lucidum in all parts are homologous 

 with the epitrichium, must be decided by fuither investigations. 



Änatomisclie Gesellscliaft. 



In die Gesellschaft eingetreten : Prof. Dr. W. Leche in Stockholm. 



Personalia. 



Zürich. Dr. W. Felix, früher Assistent am anat. Institut zu Würz- 

 burg, ist zum Prosektor am anat. Institut ernannt worden. 



: iju>:uuruclwi=ici(.lii;i"ii"" l'uUlej ill Je 



