14 BOTANICAL GAZETTE [JANUARY 
The detailed data are given in table III. The figures given 
under average width represent the averages of forty individual 
measurements. Only seeds that had shown an initial increase in 
diameter and were green were included. 
In this experiment another interesting observation was made. 
Just previous to the formation of the leaf point, the embryos were 
gorged with starch. With the formation of the leaf, however, there 
was a disappearance of the starch, it having been converted into 
TABLE IIT 
pantera Pie CONCENTRATION OF GLUCOSE, Epidendron i mreedgeing inosmun; 
DS PLANTED DECEMBER 8, 1920; NOTES TAKEN 1921 
WIDTH OF EMBRYOS 
C IN MICRONS PER- 
x fs ULTURE CENTAGE 
CULTURE SOLUTION _NO. a S macs REMARKS 
ini- axi- LEAVE: 
sae catia Average 
Pal URE, cc ee oa 416 | 408) TAR se 93% no a 
a nuient ha oats glucose 
194 | 582 | 446] 20 | 50% no change 
99 339 | 582 | 446] 10 | 30% no change 
104 | 291 | 630 | 446| 10 | 25% no change 
‘ull nutrient-+1.00% glucose 
Full nutrient + 2.00% glucose} 
sugar, as evidenced by the fact that some of the embryos still 4 | 
showed a slight presence of dextrins. 
Influence of microorganisms 
Throughout the various experiments made a few cultures always _ 
became contaminated. Generally, if the contamination was 4 _ 
Penicillium, the embryos became covered by the mycelium and 
death resulted. Those embryos not covered often showed a marked — 
increase in growth over the embryos in the corresponding uncon- — 
taminated cultures. The increase in growth may have been due 
to one or a combination of the following: an increase in the carbon 
dioxide content of the tube; a change in the chemical character 
of the nutrient medium, brought about either by secretion of organic 
substances from the fungus or by products produced on decomposi- 
tion of the fungus; or changes in the sugar effected by extracellular — 
biseat Sov action. 
es ea — a H Tet Nate ee s Sn ee ‘ Pa es 
Be Ralhos Sao oot: er Cot eh fe Serene ery Nudes Taker I Se Ih ere le RE | Ss TH 2k Casa eee es 
