1 90 Oranges and Lemons of India. 



of the oil cells, which are so constant a character in all 

 parts of the citrus bark, leaves, petiole wings, petals, 

 rind ? My reply would be that they have been trans- 

 formed into pulp vesicles. 



I think the digitate citrus, as I shall endeavour to 

 explain further on, gives us some idea of how, accord- 

 ing to my theory, the oil cells of the carpels were 

 changed into pulp cells. 



This transformation might, perhaps, appear a great 

 stretch of the imagination, but wherever we look, we 

 find that nature has worked her ways with a compara- 

 tively small number of organs, fashioning them for all 

 sorts of purposes as she progressed ; here, using the 

 hand for progression only, there for progression and 

 prehension, and afterwards for prehension only, and as 

 an instrument of the mind. In another instance, we 

 find the nose, still an organ of scent, immensely 

 lengthened and becoming also an organ of prehension. 

 The tail, in other instances, has become an organ of 

 prehension, and so on with other parts of the animal 

 organism. 



With regard to insects, Dr. Duncan, in his " Trans- 

 formation of Insects," p. 9, says : "If the skin of a 

 caterpillar, a chrysalis, and a butterfly be examined, 

 the marvellously beautiful cells and hairs of the perfect 

 insect can be seen to be modified epidermal cells, whose 

 predecessors were infinitely more simple and less 

 elegant in the immature insect." 



At p. 30, he further states, regarding the silk-pro- 

 ducing organs of insects, that " these long tubes form 

 the web or silk-spinning apparatus in the larva ; but 

 after the cocoon is finished, and the first transformation 

 takes place, not only do they become small, but their 

 function alters. The small glands of the perfect insect 

 secrete saliva instead of web, and assist in digestion." 



