524 0. CLIFFORD DOBELL. 



cytoplasm. It is a substance, moreover, which maybe stained 

 red with Giemsa's stain (cf . figs. 3, 10), From this it may 

 perhaps be inferred that the granules are composed of a 

 chromatin substance, and are therefore of a nuclear nature. 

 This consideration, however, does not i-eally justify the con- 

 clusion that the granules constitute the nuclear apparatus. 

 Further evidence of the behaviour of the granules during 

 other phases of the life-history is required before their true 

 significance can be settled. Yet for the present, I regard 

 the nuclear hypothesis as the most probable, and believe that 

 the granules represent a chromidial nucleus somewhat similar 

 to that which occurs in many Bacteria (see Dobell, 1910a), 

 and some Protozoa. 



To summarise my interpretation of the protoplasmic 

 structure of Cristispira: The whole body is composed of 

 a single series of cylindrical chambers or alveoli, separated 

 from one another by disc-like partitions. These structures 

 are composed of a denser cytoplasm constituting their walls, 

 and a less dense cytoplasm which fills the chambers. Very 

 small granules — probably constituting, as a whole, a nucleus 

 of a chromidial form — are arranged round the circumference 

 of each disc-like partition. Various appearances — such as 

 a series of pairs of large granules, tetrads, transverse bars, 

 spiral filaments, etc., of chromatin — which are often encoun- 

 tered, and have been frequently described by others, are 

 artifacts. 



One more point in the protoplasmic structure of Cristi- 

 spira veneris requires consideration. It often happens 

 that here and there, in the body of an individual, certain 

 chambers appear more darkly stained than the remainder. 

 This appearance is well seen at the point marked a in the 

 individual depicted in fig. 6. At other times the partitions 

 between the chambei-s appear thickened (see fig. 8, h, etc.), 

 and appearances which are intermediate between a darker 

 chamber and a thickened septum ai'e also to be seen (see 

 fig. 9, where this is shown in two places). Similar appearances 

 have been figured by Gross and others. 



