130 J. J. LISTER. 



prior to the production of the young, individuals presenting 

 differences in the form and size of shell, had come together in 

 pairs on the side of the vessel. These individuals, he suggests, 

 were male and female. 



In 1854, Max Schultze published his work 'tjber den 

 Organismus der Polythalamien ' (38). In it he described and 

 figured young individuals of Miliolidse and Rotalidse. Examples 

 of young Miliolidas, consisting only of a spherical central 

 chamber and tubular second chamber, are figured, and others in 

 various stages of growth. He was struck by the marked 

 difference in size of the central chamber presented by examples 

 of the former group. From the figures it appears that the 

 long diameter of the central chamber was in some cases 170 /i, 

 and in others 35 fi. As will be shown below, these figures 

 correspond approximately with the diameters of the central 

 chambers in the megalospheric and microspheric forms of 

 Biloculina depressa, D'Orb., one of the Miliolidse (woodcut, p. 

 114). Schultze, however, did not recognize the existence of 

 dimorphism, and referred the individuals to different species. 



In 1856, Schultze made a further contribution (39) to the 

 life-history of the Foraminifera. On May 15th, an example of 

 the genus Triloculina which had been kept in sea-water, after 

 remaining stationary on the wall of the vessel from 8 to 14 

 days, produced some 40 young. They were composed of colour- 

 less protoplasm contained in a shell consisting of a central 

 chamber, having a diameter of 54 /tt, and a tubular second 

 chamber coiled about it. These gradually crawled away over 

 the glass by means of pseudopodia. On breaking open the 

 chambers of the parent shell, only a little granular material 

 was found, and Schultze concludes that all or nearly all the 

 contents had been fashioned into the young. It is stated that 

 the parent of the young Triloculinas was conspicuous by its 

 larger size, among the other examples present. 



In the same paper ScHULTZE described a form with a 

 siliceous shell, which he provisionally called Nonionina silicea, 

 in which numbers of spheres with siliceous coats, having a 

 diameter of about 97 fi, were present in the chambers. The 



