403 JENNINGS— HEREDITY IN PROTOZOA. [April 24, 



Table V. 



Correlation Tabic for Length and Breadth of a Random Sample Descended 



from the Single Large Individual D, taken from Culture i, and 



allowed to Multiply 60 Days. (See polygons D, Diagrams i and 2.) 



Length in Microns. 



COMVOO^COM^O'-t-COn^O'^CON^O^COM^O -rt CO 

 CS rOro-^'^^uouovOvDvOr^t^COCOOD 0^a^0 O O i-i >-i a ^ cs 



l_MM|_l-IMMI-.Ml-l^-ll-(l-ll-ll-l>H>-ll-lCSCStMf<P)e< c< P) 



I 

 I 

 6 

 13 

 13 

 23 

 18 



13 

 5 

 5 



I 

 o 



I 



loooooi I I 14211614189946262101 



Length — Mean, 188.360 ± .980/^ Breadth — Mean, 49.000 ± .548," 



St. Dev., 14.532 ± .6g2fi St. Dev., 8.144 ± .388/" 



Coef. Van, 7.715 ± .370 Coef. Van, 16.618 ± .814 



Mean Index, 26.029 per cent.; Coef. Cor., .4188 ± .0556. 



guished under the names Paranicciiiin anrclia Miiller and Para- 

 incciujii cmidatum Ehr. The two groups we have found correspond 

 to the descriptions heretofore given of the two species, the smaller 

 set representing Paramecium anrelia, the larger Paramecium can- 

 datum. Besides the differences in size certain other characteristics 

 have been held to distinguish the two species, and these distinguish- 

 ing characteristics are evident in our two grottps. Paramecium 

 aurelia is described as having two micronuclei and P. caudatuin but 

 one ; this is true for our larger and smaller groups respectively. 

 Paramecium aurelia is said to be more rounded beliind, while P. 

 caudaturn is pointed. In spite of many variations in form within 

 each group, it is clear that our smaller group corresponds in this 

 respect also with P. aurelia, the larger one with P. caudaturn. 



Calkins (1906) has brought forward evidence tending to show 

 that the supposed distinction into permanently differentiated forms 

 is not well based, so that there are not two species, the different sizes 

 being merely variants of one. Calkins based his doubts as to the 



