ON THE LIFE-HISTORY OF THE FORAMINIFERA. 157 



these specimens numbers of rounded bodies, which appear to 

 be nuclei, can be detected in the protoplasm. 



In three examples of the megalospheric form, while the 

 central chambers of the shell are empty, those at the periphery 

 have the form of brood chambers, and are crowded with young 

 " primitive discs," similar to that whose empty chambers occupy 

 the centre of the parent shell (figs. .50 and 51). 



The young are disposed in the brood chambers in the same 

 way as in the microspheric forms from Tonga and Fiji, above 

 described, except that, owing to the thinness of the margin of 

 the disc, as compared with these specimens, the young in each 

 annulus are in a single row. I have failed to recognise a 

 nucleus in the young form, probably owing to the imperfect 

 preservation. The specimens containing young belong to a 

 batch collected in the month of November. 



We are here then brought face to face with the fact that in 

 this species megalospheric young are produced by megalospheric 

 parents, while it is no less certain that (in Fijian specimens, as 

 described by Brady, and in Tongan specimens, as I have shown) 

 megalospheric young are produced by microspheric parents. 

 The relation of the two forms to one another will be discussed 

 at the end of this paper*. 



It may be pointed out here that, in the Tongan specimens, 

 the nuclear characters of the two forms agree fairly well with 

 those of Polystomella. 



In the microspheric form numbers of rounded nuclei are 

 found scattered through the protoplasm, and they may be found 

 in process of simple division. I have not, however, recognised 

 anything like the giving off of deeply staining strands, which is 

 so marked a feature in Polystomella. 



In the megalospheric form, a single nucleus is found during 

 a large part of the growth of the individual, and ultimately it 

 appears to break up into a number of fragments. 



In Polystomella, as we have seen, the nucleus of the me- 

 galospheric form increases in size with the growth of the 



* See p. 169. 

 VOL. VI. 1^ 



