12 Transactions of ttie Society. 



happens to a certain extent in Patella, but at the end of oogenesis 

 a Lirge number of the elements appear to be discarded where their 

 function is fulfdled and they form perijtheral layers of lipoid 

 substance outside the nucleus and inside the vitelline membrane, 

 while others seem to remain attached to the sides of the yolk 

 spheres. 



From a consideration of a number of cases of oogenesis it is 

 evident that the (xolgi apparatus and mitochondria are quite 

 distinct, although there seems to be a decided relationship of function 

 between them. They seem to be semi-independent, but probably 

 under the controlling influence of tlie nucleus, so that the cell as 

 a wliole is a complex unified system. A\\y attem|)t to explain the 

 metabolism of the cell must take into consideration the part which 

 eacli cell organ plays and the relationship of function which exists 

 between them ; a task which in the light of our present knowledge 

 must be confessed to be an impossibility. 



Although both Golgi apparatus and mitochondria are present 

 in the youngest oocytes they do not always develop concurrently. 

 In Limntva (■>') the latter organs s])read out in the cytoplasm 

 slightly more rapidly than tlie former; however, in Patella the 

 mitochondria do not begin to disperse until the Golgi elements are 

 well spread throughout the cell. In the Ascidian egg the dispersal 

 of mitochondria has progressed considerably before the Cuilgi 

 apparatus passes out of the net-like com])lex condition; but the 

 mitochondrial content as a whole is smaller in bulk than that of 

 the Golgi apparatus, tlie reverse is the case in Liinntva. These 

 differences appear to be related to the part the cytoplasmic organs 

 play in the formation of yolk. In the Ascidian oocyte it is the 

 mitochondrial granules which enlarge, become swollen with yolk, 

 and combine with the Golgi elements ; but in Patella the Golgi 

 elements influence the formation of }olk, and the mitochondria 

 play no direct part in the process, so that they do not become 

 active in the cell until yolk formation is much advanced. 



The exact function of mitochondria and Golgi apparatus is still 

 a matter of controversy. Meves and Duesberg think that the 

 former may be the bearers of the hypothetical cytoplasmic organ- 

 forming substance which determines the development of the 

 various parts of the body during organogeny, but owing to the 

 diversity of l)ehaviour of these cytoplasmic bodies in different 

 organisms .this view seems hardlv likelv. I have not studied 

 organogeny in Patella, but from a perusal of the literature and 

 investigation of the oogenesis it seems to me much more likely that 

 the mitochondria and Golgi apparatus are especially concerned with 

 the general metabolism of the cell at certain stages of growth. Their 

 spreading out in the growing oocyte is probably to be accounted for 

 as a means of influencing the cytoplasm, and also as a preparation 

 for equal distribution when the cell divides- in embryogeny. It 



