30 
The Ohio Naturalist.. 
[Vol. IV, No. 2 , 
as he is by transniissionists, both as men of science on the one 
hand and with fanciers on the other, one would expect him to 
follow. But he does not, and as a conclusion to these remarks 
and as an expression of what the speaker deems the sentiment of 
those biologists who have worked more especially in this field, 
the following summary of his experiments, given by himself before 
the British Association, is appended : “In nn- experiments I 
have never seen anything that would point to the transmission of 
an acquired character.’’ 
Note. — Since the above was prepared, a volume from Macmil- 
lan & Co., written by Thomas Hunt Morgan and entitled “ Invo- 
lution and Adaptation’’ has appeared. In this book is found a 
treatment of the general subject in the light of recent research. 
It maj’ be said that the transmis.sion lu’pothesis is not counte- 
nanced b}’ this author. 
NOTES ON THE NUTATION OF PLANTS. 
JOHX H. SCHAFFXER. 
In the summer of 1896, the writer studied the nutation of Hel- 
ianthus annuus ( i ) and found that in this plant we have one of 
the most remarkable and striking diurnal phenomena to be ob- 
served in the plant kingdom. It has been believed quite generally 
that the disc of flowers follows the sun but Kellerman (2) showed 
conclusively that this is not the case. The nutation occurs in the 
upper part of the stem before anthesis, the terminal ro.sette fol- 
lowing the sun from morning until sunset. Along with H. annu 
us, H. scaberrimus was studied and found to act in the .same 
way. 
In 1900, the cultivated variety of H. annuus was reported (3) 
to nutate as strongly as the wild variety, and the same was 
observed in regard to H. petiolaris. 
More recently Stevens (4) has shown that a similar nutation 
occurs in various other genera of widel}' .separated families. He 
found nutation in Bidens frondo.sa and Ambro.sia artemi.saefolia. 
He als» mentions the genera, Amaranthus, Lespedeza, Melilotus 
(especially M. alba), Medicago, and Trifolium, as containing 
species which show more or less nutation. 
During the past summer numerous observations were made on 
various plants in Cla}' count}-, Kansas. 
The writer had himself noticed the nutation of Ambrosia trifida 
in 1897, d was not included in a previous report as no careful 
observations had been made. The giant ragweed nutates very 
decidedly when conditions are favorable, often bending 90° to the 
west in the evening. In the morning the bending of the stem is 
