134 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
across Port Erin Bay. The high peaks in April and 
May, and then again, but to a less extent, in September 
and October, show the influence of the vernal and 
autumnal phyto-plankton maxima, and the effect would, 
of course, be still more marked in the curve showing the 
Diatoms alone. The autumn rise would in the curve for 
some years be greater than is shown in this particular 
































case. 
BSEnRRas Baaw [| aS REMORSE Beas 
q Fa SU EGSeUe COGEUE HEEL UUEEEPSensseee"ecerentee 
fe | | Be N ri {Terao erie pyaty- yo. | | 
2ol__] | Tl | FU af ei: ac a ee fw am fe Te | i a 
i ea a a ete d tat Et ttf TOA L PLANKTON ini ce 
pat | SERASOR I | | [| os fe pL 
SESE ST Poe aR 
oeae 1 | IH ARH Pe latch. ele 
BEER EEE EEE EHR EEE acta eee Ree 
VLORIELIN Avieramges 
BeGSEE ai | WN eae fa BYRNE Skew 
EERE 
H+ aA AE AN aE 
Hoatastectaatese aut ict sectesteattasti fasts 
4EBOBm iz Be AH Nt | ed ESeniisaees 
SRAM Ee H+ Ht REE tt 
ee ers] PT aT TaN isl Bee Hb pte 
sbaeeeraanes see aneenuaesat esse senaeefasctate 
Se ECCT RSNA eae 
LE COREE eae CPE 

Higa 
Taking the average of the last two years (see the 
solid black columns in fig. 2) in Port Erin Bay, we find 
that the monthly averages for the total plankton begin 
low in January and February, rise in March and still 
more in April, reach the maximum in May, drop rapidly 
through June, July and August to the summer 
minimum, rise a little in September and October to 
form the autumnal maximum, and fall again in 
November and December to the mid-winter minimum. 
In the previous year (1907), as will be seen from the 
other columns, the vernal maximum was a month 
earlier, and of great magnitude. The autumnal 
maximum is generally very much less than the vernal 
