225 
of both heat and moisture, in which case all annual periodicity dis- 
appears and the plant goes through its cycle of vegetation independ- 
ent of the months of the year, as in the warm and rainy regions of 
Java. 
As before said, the absolute value of the ratio f/w need not be 
considered at present, and in fact it changes with the units of time, 
of temperature, or rainfall, ete. Linsser divides the depth of the 
monthly rainfall, expressed in Paris or French lines, by the average 
temperatures of the respective months expressed in degrees Centi- 
grade. 
In order to ascertain which of his European stations lies in the 
zone A and which in the zone B it is necessary to adopt some limit- 
ing value for the ratio f/w, and to this end Linsser examines these 
ratios in connection with the phenomena of plant life, adopting the 
principle that as two plants from different places, accustomed to 
different quantities of heat, behave differently when they both receive 
the same quantity of heat, so also two plants from places having dif- 
ferent distributions of rain will behave differently and arrive at the 
same phase at different times when they are brought into the same 
place or under the same local climatic influences as to moisture and 
temperature. 
In order to decide as to the limiting value Linsser studies the 
ratios for the hottest months of the year, which all relate to the 
ripening phases of vegetation, and finds that for the units of measure 
adopted by him the value of ratio //w, that represents approximately 
a dividing line between the stations that have an abundance of rain 
in summer relative to the summer heat and those that have little rain 
relative to the heat, is 1.2. I have indicated in the preceding table 
by the letters A and B the stations that have f/w>1.2 and f/w<1.2, 
and which Linsser puts into his zones of abundant and scanty sum- 
mer rains, respectively. 
I give in the following table some of the more striking and perma- 
nently important results of Linsser’s computations. His original 
work, based on about 30,000 observations, gives for each of his 31 sta- 
tions and for 118 species of plants and for each of the three phases— 
leafing, blossoming, and ripening—the ordinary phenological con- 
stant or sum total of mean daily temperatures above 0° C., and also 
his own physiological constant, which is the ratio of this sum total 
to the annual sum total for the station. In the following summary 
I give the physiological constant as it results from the average of 
all the individual stations in the zone A; but for the sake of quicker 
comparison between the results for zones A and B the summary gives 
not the physiological constant for B, but its departure or difference 
2667—05 m——15 
