STEPHEN HALES 137 



plant-house designed by him for the Dowager 

 Princess of Wales, in which warm fresh air was 

 admitted. The house in question was built in 1 761 

 in the Princess's garden at Kew, which afterwards 

 became what we now know as Kew Gardens. The 

 site of Hales' greenhouse, which was only pulled 

 down in 1861, is marked by a big wistaria which 

 formerly grew on the greenhouse wall. It should 

 be recorded that Sir W. Thiselton-Dyer^ planned a 

 similar arrangement independently of Hales, and 

 found it produced a marked improvement of the 

 well-being of the plants. 



It is worthy of note, that though Hales must 

 have known Malpighi's theory of the function 

 of leaves (which was broadly speaking the same as 

 his own), he does not as far as I know refer to it. 

 In his preface (p. ii.) he regrets that Malpighi and 

 Grew, whose anatomical knowledge he appreciated, 

 had not "fortuned to have fallen into this statical* 

 way of inquiry." I believe he means an inquiry 

 of an experimental nature, and I think it was 

 because Malpighi's theory was dependent on 

 analogy rather than on ascertained facts that it 

 influenced Hales so little. 



There is another part of physiology on which 

 Hales threw light. He was the first, I believe, to 

 investigate the distribution of growth in developing 



* The above account of Hales' connexion with the Royal 

 Gardens at Kew is from the Kew Bulletin, 1891, p. 289. 



' I am indebted to Sir E. Thorpe for a definition of statical- 

 " Statical (Med.) noting the physical phenomena presented by 

 organised bodies in contradiction to the organic or vital." (Worcester's 

 Dictionary. 1889.) 



