THE book is not a novel" is a phrase often in the mouth of critics, who on second thoughts might, perhaps, add with less emphasis, "It does not conform to the common type of novel." Fortified, however, with that sense of rectitude that dictates conformity to our neighbours and a safe acquiescence in the mysterious movements of public taste, the critics have exclaimed with touching unanimity-"What a pity Jefferies tried to write novels Why didn't he stick to essays in natural history "