60 Richard H. Boerker 
so as to make it an ideal soil for germination. Hence we might 
expect to find the longest germination periods in the sand. ' The 
average figures show that this is the case in each group of species. 
The shortest periods in every case are either in the loam or the 
gravel because loam is unfavorable from one standpoint and 
gravel from another. 
In comparing the check cultures of the three groups of species 
it will be seen that xerophilous species germinate first, xero- 
mesophilous next, and mesophilous last. In other words the 
drier the habitat the sooner germination starts, granting that the 
conditions are favorable. 
TABLE XE 
Tue Errect oF Light AND Soil Texture ON THE GERMINATION OF Mesophi- 
lous SPECIES 
Light Soil Texture 
Galture | ‘Shade’ | Stade | Gattare | Sand | Gravel 
Species : ls 
eI WEY BS)) LS BS Pei] SS Lea S29) Le Se £e 
PINUS CCG eee eee BAO s4an| On IBZ) a Smale At eNom al 28-0 ht2 snl 4Onelnr 
Catalpa speciosa (Ind.)....|18 I (0) 16 18 I ® | © | © | @ 
Owercus 7b7. Caren ere 40 !28 /30 |18 |26 |42 |40 |28 |38 |46 |30 |54 
Betula papyrifera........ yah Ip ae gah Ae Nigh ae Neva ae Neva hae ligak Iho 
Pinus lambertiana....... FO NZO. FOUR ZO 7O 24. 70m | ZOn 1S 2in| LOMe | SOmn Es 
INGWES (OE BOHUCDs bo 00 bape 6 44 |52 |24 |54-|36 |54 |44 |52 |96 | 2 |50 |48 
Sequoia washingtoniana...|16 |18 |16 | 6 |14 |14 |16 |18 |16 j|24 |22 I 
Tsuga heterophylla....... 66 I (0) fo) fo) Oo |66 I 144 |42 |56 8 
IPT CE GRSLERCTUSUS oe 22 |60 |18 .|64 |14 |36 |22 |60 |r8 |64 |I8 [64 
Pseudotsuga taxifolia | 
QWash Di atisre roe By NX} NBA GAL lta NOB lan 198 las 44 36 48 
AMUSE KAS A oblaco bo oo B16 35-9 28.6|/31.7|/27.9|30.0/30.1/38.7 25.5/40.4 27.9 40.7 27.0 
Tables similar to X, XI, and XII were constructed showing the 
effect of these habitat factors upon the germination per cent. of 
the species. This table is not given but the most significant facts 
which it shows are given here and in a later table. It is interesting 
to note that of the 37 species used in the experiments the highest 
* Catalpa speciosa and Tsuga heterophylla not included in averages of 
light cultures. Catalpa speciosa not included in soil-texture averages. 
