98 BOTANICAL GAZETTE [FEBRUARY 
I give the average number of spores per hole, and columns II give 
the percentages of turning toward the holes. 
TABLE VI 
S x Mucor 
uatoorssis| MO Bomaceens-| “yea |: eee 
CoNnTRASTED CULTURES IN GELATIN NIGRA ee ee GENA LONIFER 
2 : : AVE] S4. [15 (Ol 24 | O.8) 27 || 5.0) 207) Essig 
Non-nutrient : M/4 dextrose..... re hoe 26 | ae | we | er [5 gh ee eae 
: $.5] 24.| 4.2| 25 | 8.3] 29 | 4.8] 26 | 5.0) 25 
M/4 dextrose : M/a dextrose..... ae | ae | 2g \-au.} 2 | 47. | a | 96 | oe 
M/4 dextrose : non-nutrient...... 8.0] 25 | 7.7| 26 | 6.7) 28 | 6.0] 28 | 6.3) 31 
BY 35 | 7-1 36 33 37 | 1 ae 
xt ; . e ; 3-01 33° | 5:0) 30 oO 3h | 4: 22 I 
Non-nutrient : non-nutrient...... Bel got c6 | ad | x8 | aot ep | oe] ee 
Soe 3.01 30:|. 464] 27-|-6.3| 20 |-7.0|-28-| 27.729 
M/ 4 glycerin : M/4 dextrose..... ag ely oe er ers re ee 3% pf 
i Kine: Ss 0rad t-§. 3) 28%) 6.3) 28° | 5.0) 27) 83 
Non-nutrient : 0.01% CuSO,.... sod an bas ae|ar | ga} 2) oe ee 
There is indication that the number of hyphae in a given area 
and the amount of turning from that area are correlated. It may 
be said of this, as of succeeding tests, that it is at best only relative. 
It is manifestly impossible to eliminate growing hyphae from the 
experiments, and their effect is the very factor to be tested. 
A test was made by comparing preparations in which only one 
layer of gelatin was inoculated, with preparations in which both 
layers were inoculated. Two parallel series were prepared: in one 
the spores in the lower layer were about twice as numerous as in the 
other series. An examination of Table VII, which gives the results, 
shows that the percentage of turning toward a layer containing 
hyphae is less than toward a sterile layer; and in either case the 
abundance of mycelium in the layer influences directly the turning 
TABLE VII 
Montnta STERIGMATOCYSTIS | Mtcor sToLo- 
NiORA ahies Mucor MUCEDO 
I II Til I II Itt I I Ii I II Ill I Il ul 
6.5 | 0. |: 26:4 6.6) ot 92 beet Ot ee) are oh ge o | 28 
taj 0: | 35. .45 | @y go | tA} oO 1 ae 8 4540) oe) ee te 
4-5} 7 | 9615.01) 8 | os 14.51: > 4 36-1 47 | 45-1} 98 @ | 10 4 me 
9 G4 oa) 19 8 ae be tS 24-0. 30.135 1.40 fF 29 
