THE EMBEDDING OF' THE OVUM. 47 



In sections 22 (Fig. 7) and 27 (Fig. 8 'Plate IV) the fibrinous 

 cover appears in a considerably changed form. Like a catter- 

 pillar with a large head, it lies on the ovular envelope, which has 

 become thinner. Under its right and left edge (Fig. 7) traces 

 of surface epithelium are seen. Its superficial portion contains 

 a few white blood cells, in its interior a delicate network of 

 fibres. Most conspicuous, however, is the folded appearance of 

 the coagulated .mass to the right (Fig. 8 fi) which depresses the 

 ovular envelope. 



These conditions are most plainly visible in Fig. 9 (Plate V) 

 and Fig. 11 (Plate VII). In the latter, representing section 30, 

 at fi., fibrinous masses, like frozen waves, are heaped one upon 

 the other, causing a deep indentation of the walls of the ovular 

 chamber. In Fig. 13 the fibrinous masses contain a large amount 

 of white blood cells, still more of them in Figs. 16 and 17, while 

 in Fig. 15 the clubbed end of the cover is the thickest. Here 

 over the depressed portion of the ovular envelope the fibrinous 

 masses are arranged exactly like in a corpus luteum in the stage 

 of organization. 



Gradually the arrangement and signs of an organization make 

 their appearance in the fibrin cover in form of connective tissue 

 fibrils. Thus a sort of new formed protective layer develops 

 over a portion of the ovular envelope. This portion in itself is 

 very thin, but is further weakened by trophoblastic processes 

 which, as will be described later, for the purpose of fixing the 

 Eianlage, have penetrated into the summit of the ovular cham- 

 ber. (Compare Peters.) 



The formation of a protective cover for which the escaping 

 blood droplets have been utilized, must be regarded, as has al- 

 ready been emphasized by Peters, an exceedingly important 

 process and a wise provision of nature. 



If Figs. 18 and 19 (sections 68-69) are compared it will be 

 seen that the left portion of the fibrinous band has undergone a 

 certain organization and reenforces the ovular envelope. The 

 right clubbed shaped end is a mass of twisted fibrils which has 

 gradually decreased in size and like a button (Fig. 19 kn) lies 

 in a depression. 



Since with section 70 the larger of the coagulated drops disap- 

 pears, it must be assumed that the surface between sections 70 

 and 75 (Figs. 19 and 20 Plate XI) is free of any fresh deposit 

 of fibrin, carries, however, the continuation of the organized 

 portion. 



In section 75 (Fig. 20) suddenly a new fibrinous layer ap- 

 pears. To the left of the mass, which is in a state of organiza- 



