409 
1899. 
(Table VIII., XII.; Pl. XXXIX., L.) 
There are 7 collections at fortnightly intervals in the first 
3 months of the year, with an average of 1.21 em.* per m.* to .41 
in channel waters. With the exception of four days in Febru- 
ary, river levels were above 6 ft. throughout the period, and con- 
sequently the lake was continually receiving water at the north- 
ern end and discharging at the southern, and contributing 
throughout the whole time, in this way or through the slough, 
to channel waters. The average result is an enrichment of the 
plankton of channel waters. ‘The monthly averages (see table 
between pp. 342 and 343) in January and February in the lake 
exceed those in the channel by 9- and 2-fold respectively, while 
those of March, in highest flood waters, are respectively .28 
and .21 em.*, owing, as will be seen on a comparison of Plates 
XIII. and XXXIX., to the distribution of the dates rather than 
toan actual smaller production. A comparison of all coinci- 
dent collections in lake and river exhibits lkewise a larger 
plankton content in every instance in lake waters. The lake 
thus tends continually during this period to enrich by its run- 
off the plankton content of channel waters. 
The similarity in the movement in production noted in 
1598 is interrupted in these winter months by dislocations of 
the apices of the slight pulses of production, due in part to the 
flushing action of sudden floods and its unequal distribution in 
channel and backwaters. Of 7 possible agreements in the di- 
rection of movement in production there are but 3 realized in 
the case of both the river and Quiver Lake. A comparison of 
the three plates (XIII, XXIX., and XXXIX.) will, however, 
show that all, in common, exhibit evidences of a January and 
a February pulse and a common March decline. 
SUMMARY. 
The grand average of all the Thompson’s Lake collections 
shows a plankton content of 7.94 cm,’ per m,‘in comparison with 
