GENETICS: K. S. LASHLEY 
299 
clone (A) bred during the first three months was 6.463 ^ 0.013; the av- 
erage number of tentacles of 1395 members of the other (D) was 5.793 
± 0.011; the difference between these averages is 0.724 =±= 0.017. At 
the end of three months a single polyp was taken from each clone and 
used to found another clone. The average number of tentacles of the 
subordinate clone obtained in this way from .clone A was 6.907 =t= 
0.026; that of the clone derived from D was 5.844 ± 0.029; the differ- 
ence is 1.063 =»= 0.039, in the same direction as before. At different 
times during the history of the clones the number of tentacles of the 
buds fluctuated considerably but the difference between the averages 
of the buds produced at the same time by the two remained fairly con- 
stant. The minimum difference in any one week of cultivation was 
0.449 =±= 0.042, the maximum difference, 1.063 =t 0.039. Small groups 
of polyps from the two clones were kept in mass cultures under partly 
controlled environmental conditions, such as reduced food supply. Un- 
der such conditions the difference persisted so long as the two clones 
were kept under the same environment. 
These clones differed in other respects besides the average number 
of tentacles. The polyps of clone A were, on the average, more than 
twice as large as those of clone D, the average for the two being: A = 
0.869 =t: 0.021 cu. mm., D = 0.322 0.022 cu. mm: the average differ- 
ence is 0.547 ^ 0.023 cu. mm. Polyps of clone A began to produce 
buds at an average age of 3.74 =t 0.074 days, those of clone D at 4.81 
=fc 0.10 days; a difference of 1.06 0.13 days in the average age at re- 
productive maturity. 
At no time during their history did the two clones show an identity 
of characters. There were no constant differences in the environmental 
conditions under which they were cultivated and it is certain that the 
differences between the clones were the result of some internal factors. 
The clones represented hereditarily diverse races. Other diverse races 
showing somewhat less well marked differences have been found and 
seem to be of rather frequent occurrence in wild populations. No di- 
rect evidence upon the origin of such diverse races or their relation to 
sexual reproduction has been obtained. 
The inheritance of variations in the number of tentacles within the 
clone was studied by statistical methods and by the continued selection 
of variates. A comparison of the variations in the initial number of 
tentacles of parent and offspring by the use of the coefficient of correla- 
tion shows no significant resemblance between parent and offspring. 
The coefficients obtained are such as the following: 
