636 JOHN BEARD, 



Possibly in the number 8 the total of those to be classified as 

 free in the coelom has not been given. There are others, which are 

 stuck on to, or just touching the "germinal ridge", without being even 

 partly within it, and these, like Fig. 20, have been classed among the 

 normal ones. They are not very numerous, neither, strictly speaking, 

 are they rare. They also occur applied to, but not within, the peri- 

 toneal epithelium of other places. Possibly in earlier phases these 

 one and all were free in the body-cavity. Here it may be added, 

 that the accidental occurrence of such a free germ-cell in a single 

 section has never in the course of the work — except in the case of 

 Fig. 35 1) — been deemed to justify the record of the germ-cell and 

 its peculiarity of position etc. 



It has been invariably laid down, that such a free germ-cell 

 must be present in at least two, if possible in three or four, con- 

 secutive sections, and in the like position in them all. 



n. The Distribution of (jerm-Cells in earlier Embryos. 



The account of the arrangement of the germ-cells in an embryo 

 of 32 mm, at a time, when the so called "germinal ridge", or, as I 

 should prefer to call it, the germinal nidus, is well developed 

 and prominent, may have prepared the reader for still more remarkable 

 finds, concerning the various positions, taken up by germ-cells at 

 earlier periods of the development. Had the description commenced 

 with these, it is to be feared, that the account would have been re- 

 ceived with doubt and misgiving. 



In the embryo already described not a single one of the cells, 

 classed as germ-cells, could be taken to be anything else. The tyro 

 in actual embryological research and the most experienced cytologist 

 alike would at once and without the slightest hesitation admit their 

 germ-nature ^). And in this embryo we have witnessed a very wide 

 distribution of germ-cells, such that nearly a third of them are far 

 removed from the orthodox "germinal ridges". 



This condition will be found to be still more accentuated in 

 earlier embryos, where, with a few trifling exceptions, there is hardly 

 a single organ in the whole body, which is free from possible "in- 

 fection", or from the invasion of germ-cells. 



1) This figure could be replaced by others, showing germ-cells in 

 the like position and in two or more consecutive sections. 



2) The degenerating cells, shown in Plate 44, are excepted. The 

 discussion of their germ-characters is postponed to a later section. 



