THE OVA AND OVARY IN MAN AND OTHER MAMMALIA. 213 



nucleated cells (fig. 22, A,), about o-^,',yo^th or Wtv^^^ P^^'t of 

 an inch in diameter. This layer of epithelium is all that 

 remains of the germ epithelium, and it can be stripped off 

 from the ovary without difficulty. Below the epithelium, and 

 passing round the ovary, is a stratum of connective tissue, 

 consisting of elongated fusiform corpuscles. In the lower 

 part of this stratum the fibres decussate freely. Immediately 

 below this layer we come upon the remains of the large eg^:^ 

 clusters which we described in the young kitten's ovary. A 

 perfect zone, consisting of young eggs, lies immediately under 

 the stratum of tissue which passes horizontally round the 

 ovary, under the epithelium. In this zone the eggs lie very 

 close together, many of them are in actual contact. In each 

 e^g we recognise the central germinal vesicle, with its spot 

 or nucleolus — the germinal vesicles are all about the same 

 size. Belovv this zone of eggs is the general stroma of the 

 ovary, processes of which consisting of elongated fusiform 

 corpuscles and fibres, grow in between and around all the 

 eggs in the egor zone. These processes of stroma then become 

 continuous with the horizontal zone of tissue which lies ex- 

 ternal to the egg zone, and with it grow round the ovary to 

 form the tunica albuginea. As the processes of the stroma 

 of the ovary grow in between and around the young e«gs in 

 the egg zone, fusiform connective tissue corpuscles (n,n) may 

 be seen lying in contact with the yelk substance of the eggs, 

 and these fusiform corpuscles are exactly similar in apj)ear- 

 ance to the corpuscles which make up the stroma {j,J ) in 

 other parts of the ovary. Around many of the young eggs 

 the corpuscles of the membrana granulosa may be traced as 

 they develop from these fusiform connective tissue cor- 

 puscles. The nuclei of these connective tissue corpuscles 

 divide, swell up, and gradually form a wreath of little nuclei 

 round the ovum. Each little vasicular nucleus has around it 

 a small quantity of protoplasm, and in the nucleus a spot is 

 generally found. By a constant division of these corpuscles 

 the membrana granulosa at last consists of a thick layer, just 

 as in the case of the Graafian follicle in the rabbit's ovary. 



In the adult human ovary an exactly similar development 

 of membrana granulosa corpuscles can be followed out. As 

 the eggs lie imbedded in the stroma, the nuclei of those 

 elongated fibres of the stroma which are in contact with the 

 yelk substance swell up, and by constant division produce a 

 wreath of little corpuscles round the ovum. 



On comparing the epithelium on the surface of these adult 

 ovaries with the fusiform corpuscles which lie round the 

 young eggs imbedded in the stroma of the ovary, from which 



