OCCURRENCE OF LOCALIZED ANOMALIES. 



195 



It is proper to remark here that these illustrations are mostly from specimens 

 from the second 1,000 of our collection. This is because we have recently made 

 many more photographs, and, furthermore, many of the specimens in the first 

 thousand have already been figured in my paper on monsters. 



In order to render possible a comparison between localized anomalies found 

 in pathological, and those found in normal embryos, six tables have been con- 

 structed. Table 7 gives the classified distribution of the first 1,000 embryos in the 

 Carnegie Collection. The primary division comprises two classes pathological and 

 normal. The pathological specimens in turn are arranged in the seven groups just 

 described. The normal are arranged in groups to correspond as nearly as possible 

 to the ages 'of the embryos in lunar months. In order to define clearly which 

 embryos belong in a given month, I have inserted their probable lengths for each 

 month in table 12. Thus, for instance, the second month includes all specimens 

 from 2.6 mm. to 25 mm. in length, etc. (Data upon the estimated ages of embryos 

 may be found in my chapter on that subject in the Manual of Human Embryology, 

 vol. 1.) 



TABLE 7. Showing the distribution of first 1,000 accessions. 



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 

 adjustment was necessary for the reason that frequently a single number is given 

 to 2 or more specimens. Sometimes the 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 to contain 

 no remnants of an ovum, and for this reason they have to be discarded. In our 

 catalogue they are later marked as "No pregnancy." Finally, the tenth century 

 ends with embryo No. 900#. The individual entries are percentage records. Thus 

 in the fifth century there are 41 normal specimens of the second month; that is, 

 of this hundred specimens 41 per cent are normal embryos of the second month, 

 whereas the total for the full 1,000 has brought down this percentage to 24.5. 



