482 A. A. W. nUBRECHT. 



Another paper on the plaeentation of the mole by one of 

 my pupils is in preparation, and will be published in a few 

 months hence. We shall then be in the possession of sufficient 

 data concerning three European genera of Insectivora. 



Although the collecting of a sufficient number of pregnant 

 shrews appeared at the outset to be rather an arduous under- 

 takingj still an organised search, continued through three con- 

 secutive summers, furnished me with the material required. 

 Kleinenberg's fluid, in which the freshly extirpated uterus was 

 immersed in toto, proved to be in this case again — after 

 repeated comparative trials with Flemming's mixture and 

 other reagents — the best and surest means of preservation. 



The sections were cut after embedding in paraffin by means 

 of CaldwelFs or De Groot's microtome; the series were 

 numbered and catalogued in the way indicated on p. 393 of 

 vol. XXX of this Journal. 



In the explanation of the plates which belong to this article 

 the catalogue number of the respective section-series from 

 which the figures were taken is everywhere mentioned, and 

 thus a future comparison of these figures with the original 

 sections will always be possible. To such comparison I may 

 be allowed to invite any investigator, who, being occupied in a 

 similar line of research, desires to become acquainted by per- 

 sonal observation rather than by perusal of this paper with 

 the facts as they present themselves in Sorex. I must here 

 mention that not all the shrews whose uteri have served for 

 these investigations have been submitted to a separate specific 

 determination. Moreover for most of them such determina- 

 tion is at present no longer possible, as only a comparatively 

 small number (± 100) of the total series of specimens was 

 preserved. Nevertheless the possibility cannot be denied that 

 in some few rare instances the uterus may have been taken 

 not from Sorex vulgaris, L., but from Sorex (Crossopus) 

 fodiens. Pall., which latter species is provided with one tooth 

 less in each upper jaw, but corresponds externally very closely 

 with the common shrew. 



As no deviation from the normal succession of develop- 



