84 
published by HocHsTETTER, and the one hundred and thirtyfive orig- 
inal photographs considered in this study shows their greater value 
as a method of recording the external features of an embryo than 
the best published drawings. In fact experienced artists often produce 
pictures which are untrue. An artist should always control his drawings 
with good photographs of the embryo. If this is not done he makes 
a drawing in perspective and not a geometrical projection. All lateral 
projections should be geometrical. If an embryo is carefully posed 
and photographed at the natural size, enlarged prints may be made 
which are almost perfect geometrical projections. When enlarged 
fifty diameters the distortion of any part of an embryo ten millimeters 
long will not be over two millimeters. So for this purpose the best 
method of recording the profile of an embryo is a good photograph 
at about one diameter from which enlargements may be made. At 
the same time the embryo, either fresh or in formalin, should be 
accurately measured with calipers from the crown (over the middle 
of the midbrain) to the rump. In case the exact enlargement of a 
photograph is known measurements may be made from it. 
It is to be hoped that these suggestions will induce embryologists 
to record their human embryos with greater precision than hereto- 
fore, and that copies of their photographs may be placed at the 
disposal of other investigators. In the course of time it will be 
possible to arrange human embryos in stages thus permitting a com- 
parison of the structure of embryos of the same stage. In turn this 
will enable us to determine the age of embryos with greater precision. 
Nachdruck verboten, 
Uber den Processus pectinealis des StrauBenbeckens und seine 
phylogenetische Bedeutung. 
Von Dr. N. G. LEBEDINSKY, Volontärassistent am Institut. 
Mit 2 Abbildungen. 
(Aus dem Zoologischen Institut der Universität Halle a. S.) 
Am präacetabularen Darmbeinabschnitte der Vögel sehen wir 
einen ventralwärts zum Schambein gerichteten Fortsatz, Processus 
ilii acetabularis pubicus, der die vordere Umrandung des Acetabulum 
bildet. Bei vielen jungen Vögeln ist in der Acetabularregion ein 
