LOCALIZED ANOMALIES IN HUMAN EMBRYOS 



59 



may be found in my chapter on the age of embryos, contained 

 in the Manual of Human Embryology.)^ 



It will be noted in these tables that the specimens are 

 arranged in centuries; that is, each line in the table includes 

 exactly 100 specimens. The first century includes specimens 

 Nos. 1 to 98, the second, Nos. 99 to 205, and so on. This ad- 

 justment was necessary for the reason that frequently a single 

 number is given to two or more specimens. Sometimes the 



9 



Fig. 8 Normal embryo with cyclopia; in front of the eye is seen the Cyclo- 

 pean snout. No. 559 from Dr. B. J. Merrill, Stillwater, Minn. X 5. 



Fig. 9 Normal double monster. No. 249 from Prof. L. Hektoen, Chicago. 

 Natural size. 



first is called a and the second, b; or the first may be given the 

 number, and the second the letter a, etc. The second century 

 passing from Nos. 99 to 205 includes more than 100 numbers, 

 because specimens which are given a number are frequently 

 found upon further examination not to contain any remnants 

 of the ovum, and for this reason they are to be discarded. In 

 our catalogue they are later marked as 'no pregnancy.' Finally 

 the full 1000 ends with embryo No. 900g. The individual 

 entries are percentage records. Thus in the fifth century, there 



^ Determination of the age of human embryos and fetuses. Human Em- 

 bryology, Keibel and Mall, vol. 1, Chap. 8. 1910. 



