CELL SIZE AND NUCLEAR SIZE 
TABLE 7 
Cell size and nuclear size in tissue cells of sexually mature individuals of Crepidula 
plana 
| VOLUME OF 
DIMENSIONS OF | DIAMETER lsontzaaesl ama naes |) eS= 
nafs shana) (pnts CELL OF NUCLEUS) NUCLEUS posemnics See 
be Me cubic cubic jh 
Intestinal epithelium..... 11 x 11 x 12 6 Mise Petes.) lest s8 
Gastric epithelium....... | 10 x 10 x 36 8 68 | 3,382 | 1: 12.4 
Liver duct epithelium.... | 10x10x 18 6 ait etG28. 01) 1 ni4e4 
Liver cells (filled with, | | | | 
secretion products)..... ING) 5315) se etay | 6* 113 TOON eee S86 
Liver cells (without secre- | | | | 
LOMO CICS) see eee 14x 14 x 30 9 | 382 5,498 }1:14.4 
Kidney cells (containing | 
secretion products)....) 15 x 15x 15 6 113 Saya WL Sesyrss 
Eetodermal epithelium | | | | | 
(Meat ANUS). eel ca ts. I 5x 5x15 4 33 342 |: 10:3 
Gill chamber epitheium..| 6x 6x 12 4 33 405 eal ee 
Gill filament epithelium... 7x 7x 9 | + SOM ee LOS nal lana 223 
Epithelium from foot....| 6x 6x15 5 65.4 474.6/1:7.1 
Ganglion cell (large)...... Ig se it 22233 12 905 5,724 LG He 
Ganglion cell (large)...... 10 x 10 x 20 | 9 382 | 1,618 eal 
Oécytes I (before yolk | 
HOMINENENOI\)). scnococeadeor 123 | a 180 836 | 1:4.6 
Oécytes I (before volk for- 
MATION) 4 y eee tee 113 eer ol To TQM lid ike 
Odécytes I (before yolk for- | 
LINCOM) peste saben eee 10 6 113 407 Le S.@ 
Odcytes I (before yolk for- 
Mla aIOM|) eg poate cere ee 8 | 5 65.4 2OSy Tilecrord 
Odécytes I (before yolk for- | | 
TEWMIOM))s sco ceccemece son 63 4 | 33 111 12383 
*Nucleus shrunken and very irregular in shape. 
the Kernplasma-Relation being about 1:5; however in this 
case the nerve fiber is not added to the cell body and this would 
doubtless greatly increase the volume of the plasma. Muscle 
cells in Crepidula are long, slender and crooked and I have found 
it impracticable to estimate their volumes with any degree of 
accuracy. Doubtless the plasma, including the contractile sub- 
stance, is here relatively much more abundant than in embryonic 
or epithelial cells. In the epithelial and gland cells of adult 
