238 Phytotomy founded [BOOK n. 



mical relations of the fruit and the seed, the existence of the 

 embryo in the seed and its structure, and then goes on to 

 the roots. 'The roots of trees are a part of the stem, which 

 divides into branches and ultimately ends in capillary threads 

 (' capillamenta ') ; so that, in fact, trees are simply fine tubes, 

 which rim separate from one another underground but gradually 

 collect into bundles ; these bundles unite further on with other 

 and larger bundles, and all together ultimately join to form a 

 single cylinder, the stem, which then by separation of the tubes 

 at the opposite extremity stretches out its branches, and by 

 continued gradual separation of the larger into smaller finally 

 expands into leaves, and so reaches its furthest limits.' The 

 conclusion of the whole account is chiefly concerned with the 

 part played by the various kinds of tissue in the nourishment 

 of the plant. 



In the second part, published in 1674, the different kinds of 

 tissue in the stem are discussed at greater length ; here there 

 is much that is really good, but at the same time much that is 

 imperfect to an extent which cannot be attributed solely to the 

 inferiority of his microscope. Very excellent is the way in 

 which he endeavours to make out the more obvious anatomical 

 relations of the rind, the wood, and the pith, and in the 

 texture of the rind and the wood connects the longitudinal 

 course of the vessels and woody fibre with the horizontal 

 course of the medullary rays and the 'silver-grain.' The 

 magnifying powers which he used must, to judge from his 

 figures, have been very considerable ; how much of what is 

 imperfect in them is due to the indistinctness of the field of view, 

 and how much to inaccurate observation, we cannot say. For 

 instance, he sees the bordered pits in the wood of Coni- 

 fers without perceiving the central pore, and represents them 

 as coarse grains lying on the outside of the wood-cells ; it was 

 unfortunate for Malpighi, as for his successors, that the large 

 vessels in the wood of dicotyledons, to which they gave most 

 of their attention, are often filled with secondary tissue (thy- 



