472 
PLANKTON PRODUCTION AND TEMPERATURE, 
1897|81.02] 4.69] 80.9 | 3.65] 77.07 8.83 65.1 5.95|. 45.7 
1898/82 .87| 0.58] 80.56) 0.91] 71.87] 0.69 54-37| 0.24) 41.42] oO. 
{clove REY (AE eee Meee Stone Renee onmon done nononoracllogeue clsooeenllesnoc. 
January February | March | April | May | June 
u 
oO 
© ' j 1 : 1 5 ' 
DH A, | a | 4 a | a | Oo, | a | 4 
Bles| Bias] 8 ee) 6 ee | alee) |e eee 
BH }A fH Ay fH Ay H Ay HB AY ia AY 
1:0) | erences | aemeteo| erecta orition secs sacwed|sodcHs) aod ot |Scioa te 80.25] 0.74 
ito srillecone 32 OnOD|Reseaere leer 58. 2304 oeracralloaco oo 80. | 30.42 
1896|32.75| 0.01] 33.7 | ©.02| 39.52] 0.07] 64.54) 5.67] 72.7 | 1.30] 74.7 | 9.72 
1SQ7} attodl seer 32.25} 0.04] 43.8 | 0.38] 60. 5.11} 66.3 | 5.62) 75. 0.27 
1898)32.7 | 0.45] 32.12] 0.27] 43.3 | 0.33] 53.32| 4.40] 65.8 | 11.30] 78.8] 3.96 
18991329) | 0.18] 32.6 |) <0. 81/535 527 | O28 | prev mel eseicve retell eetetenstet| cami tste tele eeehenete eet 
July August September October November | December 
S eee 
pm | a | a | a | a | a | a | 
Bias § |e3s) 2 | ss oe eee eee 
| Ay i AY & AY fH | AY BR AY i Ay 
1894|82.25| 5.12] 83.5 | 9.67] 77.5 1.36] 58. 0.61} 41 0.10} 39. 0.10 
1895/79. 9.33} 80.51] 4.03} 78.87] 1.52] 54.26] 0.57) 42.5 | 3.02] 37.5 1.14 
1896|/80.7 | 1.44] 82. 1.12] 65.75] 0.38] 56. I.1I| 44 0.02] 33.6 | 0.76 
1.00] 33.02} 0.56 
fo) 
in Thompson’s Lake, 29 per cent. The difference would be in- 
creased if the aberrant data of the late autumn of 1897 were 
removed from the records. Low temperatures thus tend to 
depress production in both channel and backwaters, and high 
temperatures to increase it. 
The minimum production of the year occurs in the river, 
and with few exceptions in the backwaters, in January-Febru- 
ary, the two months of minimum temperature. With the 
period of rising temperatures in March—May there comes gen- 
erally at all of the stations a rapid rise in plankton production, 
culminating in the vernal pulse in the last days of April or the 
first of May at about 60°-70°. The effect of this is seen in the 
generally high average production in April and May in both 
channel and backwaters. With the establishment of the sum- 
mer period of maximum temperatures, which includes the 
months of June-September with the exception of a few days 
