312 JAS, J. SIMPSON—ENTOMOLOGICAL 
was no rain were November and February, At the same time, the monthly 
rainfall is also greater in the south than in the north. 
The maximum rainfall for one day for the years 1905-1908 was as follows : 
In 1905, 4°04 inches at [lorin on June 2nd ; in 1906, 7°27 inches at Zungeru ; in 
1907, 4°15 inches at Ilorin on September 9th; and in 1908, 5 inches at Torin 
in October. 
Consequently no definite periods can be given for the wet and dry seasons in 
Northern Nigeria, but in a general way it may be said that the duration of the 
dry season decreases, whereas the amount of the monthly rainfall increases from 
the north to the south, 
TABLE. C. 
Maximum and Minimum Humidity. 
] ] 
1906. 1907. | 1908. | 1909. | 1910. 
| 
Min. | Max.| Min. | Max. | Min. | Max. Max. | Min. | Max. 
Geidam — — a = 26 81 24 81 29 83 
Bauchi 22 73 _ -— oo 26 82 26 77 
Kano noc coe | — : 81 — — 27 83 28 75 
Sokoto sac Soh | — 22 86 — — 27 76 25 72 
Nafada 5 -- — -- -- — 29 81 33 84 
Katagum oe — _— — — 26 86 30 76 28 70 
Zaria... adc bo el BY? 80 _ — 32 80 31 79 33 86 
Kontagora ... socal 24 85 30 90 —- — 32 80 27 84 
Maiduguri ... — — 29 84 _ — 34 86 34 wo) 
Birnin Kebbi aie = — — — — —_ 35 91 3B) 83 
Yola... aa veal |nroe 82 33 79 — — 36 80 24 84 
Keffi... so we | _- -- a — — 36 80 36 85 
Zungeru... coe | al 55 38 82 39 84 44 89 33 86 
| [bi - coo || ll 81 40 84 — ~ 55 79 39 80 
Baro... BoC | ee — — — 55 83 59 77 58 84 
Lokoja noe sou || EY 78 61 78 75 84 64 81 59 80 
Torin 20 Son |) 28) 81 61 81 63 88 65 81 51 85 
| Ankpa see) yee fee ec are pele ff 5B, ig 88nd 167, ,] 85. 4) pG4 ag nBe 
Another factor which must be taken into account is the degree of humidity in 
the various districts. Table C has been added to show the available records for 
the years 1906-1910. It is unnecessary to analyse these in any detail, but the 
following observations may bring out the salient features :—(1) The variations in 
the maxima are very slight as compared with the minima; for example, in 1909, 
the highest and lowest maxima are 85 and 76, and the highest and lowest minima 
are 67 and 24, while the corresponding numbers for 1910 are 86 and 70, and 64 
and 24, (2) The contrast between Geidam and Ankpa, referred to above, is 
again emphasised. At the former station, the difference between the maximum 
and minimum for one year was 457 degrees in 1909, and 54 degrees in 1910, 
whereas at the latter the corresponding differences were only 18 degrees and 
22 degrees, 
