PLANKTONETTA ATLANTICA. 139 



have seen no trace of oil globules or of the other inclusions so 

 comujon in some Radiolaria. 



At the upper outer angle of the protoplasmic mass, and at 

 the most anterior point of its circumference (fig. 9), the 

 protoplasm is close and finely granular; from this point a 

 bundle of fine tubes, about seventeen to twenty-five in number, 

 penetrates through the central capsule and diaphragm, and 

 leads upwards towards a mass of extra-capsular protoplasm, 

 which is free of phseodial corpuscles. This bundle of tubes 

 corresponds to poro-arejfi, astropyles, etc., in that it connects 

 intra-capsular and extra-capsular protoplasm. It is at first 

 difficult to detect, the whole bundle being only about 11 to 25 ju 

 across, an individual tube less than 1 /j, but I have found it 

 in every series of sections. On the other hand, I have failed 

 to find any further opening in the central capsule, and do 

 not believe that such exist ; Planktonetta, therefore, would 

 seem to be Ph^odarian (Haeckel), but not Tripylarian 

 (Hertwig) , The structure of the nucleus cannot be accurately 

 determined from specimens indifferently preserved in formalin. 

 It appears to be bounded by a definite membrane, and to 

 exhibit numerous large round chromatin granules, with 

 patches of a more lightly stained plasma. All the nuclei cut 

 were in one phase, apparently a resting phase. 



With regard to the extra-capsular protoi^lasm, a large 

 irregular mass lies somewhat anteriorly near the ends of the 

 communicating tubes (fig. 9). Elsewhere it is so closely 

 packed with phteodial corpuscles and other inclusions as to be 

 hardly visible in sections. The majority of the phaeodial 

 corpuscles, as seen in a teased preparation in glycerine, can be 

 divided into the brown and the clear corpuscles. These 

 brown corpuscles are fully charged with coarse and fine 

 granules, crystals (?), etc., to Avhich they owe their colour. 

 It would seem that some of these corpuscles are excretory, 

 almost " phagocytic ; " fig. 12, a, shows one of them containing 

 an organism which, whether food or parasite, appears to be 

 a young specimen of the organism drawn in fig, 15 to the 

 same scale. A similar brown corpuscle in fig. 12, c, contains a 



