98 PROCEEDINGS OF THE ANATOMICAL AND ANTHROPOLOGICAL 



DESCRIPTION OF A HUMAN EMBRYO OF 13-14 MESODERMIC 



SOMITES. 



By ALEXANDER Low, M.A., M.B., C.M. 

 (Presented 22nd February, 1908.) 



The human embryo Pfannenstiel III. was placed at the disposal 

 of Professor Keibel, for publication in his NormenJtafel ztir Entwickel- 

 uvgsgesfMchte do* Mewclien, by Professor Pfannenstiel of Griefswald. 

 In the Normentafel the embryo is No. 6 (Fig. Vr. and Vv.). Professor 

 Keibel kindly afforded me the opportunity of studying this embryo in 

 the Anatomical Institute in Freiburg, and at his suggestion I under- 

 took to reconstruct models of the embryo according to Bora's method. 

 The work of modelling was begun in the Anatomical Institute in 

 Freiburg, and completed in the Anatomy Department, Aberdeen 

 University. 



The embryo Pfannenstiel III. was obtained at an operation, and 

 as measured through the amnion had a length of 2 - 6 mm. The embryo 

 was fixed in formalin Muller's fluid, stained in paracarmine, and 

 sectioned at a thickness of 10/x. Histologically the embryo is in an 

 excellent state of preservation. A model of the whole embryo has 

 been reconstructed at an enlargement of 100. A separate model of 

 the nervous and alimentary systems has also been made, and three 

 models of pharynx, heart with its blood-vessels, and septum trans- 

 versum at an enlargement of 150. 



EXTERNAL FORM. (Plates XI. and XII.) 



The embryo is somewhat similar to the embryo von Bulle of 

 Kollmann (7), which shows fourteen mesodermic somites and measured 

 2'5 mm. in length, but is not so far developed ; indeed, its outer form 



