95 2 
Notes. 
a total of more than twelve hundred feet. As there were seventy nodal roots, there 
must have been more than fifteen miles in length on the entire vine. There were 
certainly more than eighty thousand feet ; and of these, fifty thousand feet must have 
been produced at the rate of one thousand feet or more per day/ 
I cannot find any record that Clark’s observations have been repeated or con- 
firmed. Further, Clark does not state how the measurements were made, nor is 
there any evidence in his paper that he took these measurements himself, or checked 
them if carried out by others. Thinking that it might be worth while to estimate as 
carefully as possible the length of the root-system of another member of the same 
family, I asked the British Botanical Association, Holgate, York, to cultivate for me, 
under the most favourable conditions , a plant of Cucumis sativus , and requested the 
Scientific Director, Dr. Burt, to take special precautions as to the separation of the 
plant from the soil and preservation of all roots of whatever calibre. This, Dr. Burt 
assures me, was done with extreme care, under his own supervision. 
The plant was grown in a frame io feet by 6 feet, and was a full-sized plant 
bearing fourteen fruits, none of which were removed until quite mature, and until the 
plant was ready for lifting. The soil was washed away very carefully, beginning at one 
end of the frame and working through to the other. No roots were lost, even a few 
fibres, disconnected unavoidably in the process of removal, being preserved for sub- 
sequent measurement. The shoot region, including all the smaller branches, measured 
approximately 32 feet with about 140 leaves, counting in those that had been 
functional but had withered away at some date previous to lifting the plant. All the 
roots were then cut off close to the stem, both the primary one as well as the adventi- 
tious roots springing from the nodes. After the statements made by Nobbe, that the 
root-system of cereals may reach a length of 500 to 600 metres, and by Clark, as 
quoted above, I was much surprised to note the comparatively limited root extent of 
Cucumis sativus. After trying various methods I came to the conclusion that the only 
satisfactory way of obtaining reliable data was to stretch the root taut, and by aid of 
compass and centimetre scale to measure the length of the roots individually. The 
total length obtained was only 85-75 m., or, taking a metre as = 3-28 feet, in English 
measurements and in round numbers, 28 iL feet. The actual scale measurements 
were checked by a calculation of (a) volume, (b) dry weight. 
In the former case, the entire root-system was vacuum dried and pressed down 
in a graduated measure ; in the latter the vacuum-dried material was carefully weighed, 
the volume and weight of a definite length of roots of various thicknesses having been 
previously estimated. On the basis of the data so obtained, the volumetric estimate 
gave a length of 285! feet, and the estimate by weight 27 9J feet. It may be taken, 
therefore, that the total length of the root-system of this particular plant of Cucumis 
was about 280 feet. 
Wheat cultures were also made, but, owing to the excessive dryness of the 
summer of 191 1, the cultures were to a large extent spoilt, and it was thought better to 
discard them, and trust to obtaining more normal material in the present year. These 
measurements, for obvious reasons, have not as yet been made. 
R. J. HARVEY GIBSON, 
Hartley Botanical Laboratories, 
The University, Liverpool. 
June 6, 1912. 
