RANGE AND CLIMATE 29 



The harvest season generall}' extends over a period of four to six months 

 and exceptionally in the arid localities may be continued over the whole 

 year with such stops only as are required for overhaul and repairs. At the 

 beginning of the crop an unripe cane of lower sugar content is harvested ; 

 the percentage of sugar gradually increases and is usually at a maximum 

 in the third and fourth months of harvest, after which it decreases as the 

 cane becomes over-ripe. Taking Cuba as an example, in December the 

 cane will contain from 10 per cent, to 11 per cent, of sugar, the maximum 

 of 14-15 per cent, being obtained in March and April, after which a fall 

 occurs, which is very rapid if the crop is prolonged after the seasonal mid-j^ear 

 rains fall. It is easy to see that the combined questions of factory capacity, 

 capital cost, duration of harvest, and yield per cent, on cane form a most 

 important economic problem, which is usually further complicated by a 

 deficienc}^ in the labour supplj'. 



The ideal distribution of rainfall and temperature for an annual cane 

 crop in the northern hemisphere would be somewhat as follows. During 

 the crop period, for example from December to April, a cold dry season 

 should prevail with showers of sufficient frequency to maintain the vitality 

 of the cane without interfering with the harvest operations. During the 

 next sLx months, or from May to October, there should be a high temperature 

 combined with a heavy and well distributed precipitation. The rains 

 should fall at the rate of about two to three inches per week with absence 

 of excessive falls or of prolonged periods of drought. For one month prior 

 to harvest the rainfall and temperature should both decrease in order to stop 

 the vegetative growth and allow the cane to ripen, but complete absence of 

 water is not desirable. Finalh', it may be mentioned that early rains after 

 harvest give a cane that itself ripens early. 



Variety and Climate. — Most varieties of cane attain their maximum 

 growth in the more essentially tropical districts. Some varieties, on the 

 other hand, fail entirely when removed from these latter districts, an'd 

 others, such as those peculiar to northern India, do not succeed in the tropics. 



It seems probable that adaptability to a colder climate is a characteristic 

 of the red and purple canes. In a subsequent chapter it will be shown that 

 the light and dark Cheribon (Transparent, Bamboo, &c.) canes in all pro- 

 bability originated from striped canes. Stubbs^* states that in the relatively 

 cold climate of Louisiana a plantation of striped canes if not renewed tends to 

 pass into one of all purple canes, and he classes this phenomenon as a case of 

 the " survival of the fittest," attributing to the purple colour a greater 

 capacity to absorb heat. 



The cane known as Cavengerie, Port Mackay (in Mauritius), Louzier (in 

 Argentina), Po-a-ole (in the West Indies), is also another instance of a dark- 

 coloured cane being adapted to a cold climate. In the less tropical portions 

 of South America this variety is one of the canes most widely grown. 



In the Hawaiian Islands, the Lahaina cane forms the bulk of the crop on 

 the irrigated plantations in the arid districts, chiefly at a low altitude ; 

 it is replaced by the Yellow Caledonia on the rainfall plantations situated 

 mainly at a higher level, and hence with a colder climate. A pecuUar case 

 of suitability to climate is to be found in the D 74 cane, which has conferred 

 so great a benefit on the Louisiana industry ; suitabilit}' to the climate of 

 Louisiana is in this case due to the early maturity habit of the variet5^ 

 The adaptability of a variety to a cold climate does not always impl}^ that 



