ty pat BLOCKS FOR GROWING SEEDLIN GS_ IN 
LIQUID CULTURE SOLUTIONS? 
ConrAap HOFFMANN 
(WITH THREE FIGURES) 
In growing seedlings of any kind in nutrient solutions a suitable 
means of supporting the individual | plants is essential. The 
method commonly employed consists in the use of ordinary corks 
perforated so as to hold a varying number of seedlings. Invari- 
ably the corks are of such a size as to fit snugly in the neck of the 
vessel containing the nutrient culture solution. This apparatus, 
while satisfactory to a certain extent, offers several objections. 
The corks usually discolor the nutrient solution, the extent of 
discoloration depending upon the grade of cork employed, as well 
as upon the composition of the nutrient solution. This discolora- 
tion is due to soluble compounds, presumably organic in nature, 
which can be inferred to have some influence—beneficial or detri- 
mental—upon the growing seedlings. The corks soon warp and 
crack and become unfit for further use. Further than this, they 
furnish a substratum for molds, which frequently give trouble by 
infecting the seedlings to be grown. 
ese were some of the objections and difficulties encountered 
in the course of certain experimental work with growing seedlings. 
It was necessary in this work to grow a large number of seedlings 
in different culture solutions, which necessitated the employment 
of a large number of supports. The support which was finally 
adopted after considerable experimentation proved so satisfactory 
as to warrant its description and publication at this time. 
In place of the ordinary cork a paraffin block molded in the 
desired shape and size and perforated to suit the needs of the experi- 
ment has been used. It has been found advisable to employ a 
paraffin of comparatively high melting point, so as to prevent any 
melting or softening of the blocks under the direct rays of the sun 
to which they will be exposed in the course of their use. 
* Published with permission of Director of Wisconsin Experiment Station. 
Botanical Gazette, vol. 55] [244 
