When I casually mentioned this to a friend, he as casually replied that I had better get one in the Tigris marshes, for there they were as common as mosquitoes, and were often tamed by the Arabs. We were going to Basra to the Consulate-General to collect and answer our mail from Europe. At the Consulate-General we found that my friend’s mail had arrived but that mine had not.

Explanation:

 

When the author told a friend about his plans to domesticate an otter, the friend recommended that the author should procure an otter from the marshes around the Tigris River because they were frequently found there and were typically domesticated by the Arabs. When the narrator and his friend were travelling to Basra to the Consulate-General to collect and answer their letters from Europe, they had this chat. When they arrived, they saw that only the friend's mail had come.

 

Meanings of difficult words:

 
Sl. No
Words
Meanings
1
ValleyA low area of land between hills or mountains, typically with a river or stream flowing through it
2
CrestThe top of a mountain or hill
3
RipeHaving arrived at the fitting stage or time for a particular action or purpose
4
DownpourA heavy fall of rain
5
ShowerA brief and usually light fall of rain, hail, sleet, or snow
6
IntimatelyIn a way that involves detailed knowledge
Reference:

National Council of Educational Research and Training (2007). First Flight. Mijbil the Otter - Gavin Maxwell (pp. 102 - 110). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi..