I believe " there seems to me no great difficulty in believing" 

 that the swim-bladder in fishes ;t though originally constructed 

 for one purpose," has been " actually converted" into a lung or 

 organ used exclusively for respiration." 



I believe that the " electric organs of fishes" have been 

 produced by " Natural Selection," although it is " inipo&^ible to 

 conceive by what steps those wondrous organs have been 

 produced." I believe this, although these organs only occur in 

 species "widely remote in their affinities," while we "might have 

 expected" (on Darwinian grounds), that they would all " have 

 been specifically related to each other." I believe the same in the 

 like cases of luminous insects. 



I believe that the most simple parts of species are due to 

 Natural Selection, although I see that their "importance does not 

 seem sufficient to cause the preservation of successively varying 

 individuals." 



I believe that the tail of the giraffe has grown by degrees into 

 a " fly-flapper" (!), although I cannot explain how the species did 

 without it in previous countless ages before it grew to its 

 present length, when no doubt, there were just as many flies in 

 those hot countries, if not more, than there are now. 



I believe that every " well- developed tail" in a water animal 

 has been " worked hi" as a " fly-flapper" for land animals, or as 

 a "prehensile instrument," or to "help them in turning;" 

 although I see that in the dog it is of next to no such use at all, 

 and that the hare can double quickly enough, though with hardly 

 any tail. 



I believe that long tails are necessary to animals in hot 

 countries to give them the " power of resisting the attacks of 

 insects," although I see that sheep have heavy tails which they 

 cannot and do not make use of for any such purpose, and are 

 especially attacked by flies on their heads, which, if their tails 

 were ever so light, they could not possibly reach. 



I believe that as I hold that the swim-bladder in creatures of 

 the sea is modified into lungs in their descendants changed into 

 land animals the tail, having been so useful to the former as a 

 means of locomotion, still proves its origin hi the latter, though 

 of so little use to them. 



