14 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



The macronuclei are from twenty-five to thirty in number 

 and form a somewhat broken chain, extending around the 

 attachment disc, through the neck on the left side, around 

 the oral disc just within the band, and across above the 

 mouth to meet the left hand portion of the chain; one 

 or two are usually found on the right side of the neck 

 (fig. 18). The nuclei are in most cases entirely sepa- 

 rate, but some specimens have groups of three or four 

 within a common membrane, probably a case where com- 

 plete separation has not yet taken place after division 

 (fig. 78). 



With most stains the nuclei appear to be homogeneous, 

 but with iron-hsematoxylin considerably destained, they 

 frequently show coarse granules (fig. 79). Stained with 

 safranin, some appear homogeneous, while others contain 

 irregular, deeper staining masses (fig. 80). Picro-carmine 

 on fresh material shows granules, threads, and occasionally 

 a vacuole (fig. 81). The nuclei vary considerably in size 

 in the same and in different individuals (6 ^-7.5 A*, 3.7 

 /x-4.5 /i, 2.25 /A-6 fx, diameter of nuclei of three specimens). 

 They vary in form from spherical to oval or elliptical 

 and after fixation are often irregular in outline. The largest 

 measurement (6/^-7.5 \i) was for formalin (one per cent.) 

 fixation followed by picro-carmine stain. 



Division Phenomena. — The division stages, as observed 

 for this species of Licnofhora, agree in general outline with 

 those of L. auerbachii as given by Wallengren. There are, 

 however, many differences in detail, and more abundant 

 material has furnished a more complete series of stages. 



Changes in Form. — The first indication of approaching 

 division is increased size (fig. 18), the change being most 

 marked in the neck, which is shorter and thicker, and 

 in the oral disc, which is enlarged in all diameters. In the 

 early stages (figs. 19 to 21) there is an increase in size in 

 all directions, the attachment disc changing but little and 

 the neck becoming so broad and thick as to be hardly dis- 

 tinguishable. The whole body now increases rapidly in 



