ON THE LIFE-HISTORY OF THE FORAMINIFERA. 167 



The specimea of Calcarina hispida, Brady, described above, 

 was microspheric, and here, too, the young were probably 

 megalospheric *. 



On the other hand the production of megalospheric young 

 by megalospheric parents has been seen in several instances. 



In the specimens of Orbitolites complanata, Lamk., from 

 Celebes, described above (figs. 50 and 51), megalospheric parents 

 are giving rise to megalospheric young. 



In ScHACKO's specimen of Peneroplis proteus, d'Orb., the 

 central chambers of the young and of the parent were of the 

 same size, measiiring about 35 fi in long diameter. It seems 

 probable that they were both megalospheric. 



Max Schultze's Rotalia is said to have had a central 

 chamber of the same size as those of the young which it pro- 

 duced. The diameters of these varied from 25 to 34 /x. 

 Judging by the size of the megalosphere (37-65 yu.) and micro- 

 sphere (13 yu.) in R. Beccarii (Linn.), it appears probable that 

 this was a megalospheric individual producing megalospheric 

 young. 



Again, in the specimen of Cristellaria crepidula (FiCHT. und 

 Moll.) figured by Brady, the first chamber of the parent shell 

 measured 110 /iX 84 /a, while those of the contained young 

 varied from 60 to 30 fi. It seems clear that the parent, at any 

 rate, was megalospheric ; the nature of the young shells is less 

 evident, but the range of variation between the size of the 

 parent shell and that of the smallest young is not greater than 

 that recorded above in the size of the megalosphere among 

 different examples of Polystoniella, so that it is not impossible 

 to regard them as megalospheric also. 



5. Under certain circumstances active zoospores are pro- 

 duced by Foraminifera. 



These have been recorded by Strethill Wright in Gromia, 

 and by Murray in Cymhalopora (in specimens with the large 

 inflated chambers). 



* To these instances have now to be added PoIystomeUa crispa (Linn.) and 

 Rotalia Beccarii (Linn.), as recorded in Postscript 3, 



