Webster 1966

theories of plant movement/sensitivity first developed in the nineteenth century;

but their is a longer, lesser-studied tradition of studying plant sensitivity from the 17th and 18th centuries

"While the Renaissance herbalists were familiar with plant movements, they had little interest in the explanation of this phenomenon. Thus, they noticed that "sleep movements" were characteristic of the leaves and lowers of certain species, but they were predominantly concerned with taxonomy and medical botany." (5-6) -- didn't occur to della Porta or Cesalpino

"The greatest obstacle to the recognition of plant sensitivity was the generally accepted distinction between plants and animals, which had been accepted since the writings of Aristotle and Theophrastus -- that plants were characterized by an insensitive Vegetative Soul, while animals had a Sensitive Soul." (6)

spread of mimosa pudica in England, first half of the seventeenth century

Bacon, Syllva sylvarum (1627)

• directs attention away from experimenta lucifera (as in herbals) and toward experimenta fructifera
• emphasis on mechanistic explanations for plant sensitivity

correspondence between Thomas Browne and Henry Power on sensitive plant, shows belief that some plants have sensation like animals (14)

Charles II asks Royal Society scientists asked to study the sensitive plant in 1661 (15)

• Evelyn records the visit in his diary
• Timothy Clarke read a fuller account of the experiments in August 1661
• these accounts were incorporated into Hooke's Micrographia (1665)
• "Clarke's approach to the problem was strongly influenced by his knowledge of human anatomy." (16)

"By modifying current theories of muscular contraction, Clarke could provide a mechanical explanation for the movements of the sensitive plant." (18)

"There was a controversy between John Willis and Martin Lister over the function of the plant vascular system. Lister proposed that plants had vessels similar to the veins and arteries of mammals (which carried a nutritive sap); Wallis asserted that the veins of leaves were analogous to animal nerves and carried a nervous fluid (which was concerned with the motions due to the 'Vegetative Soul')." (18)

Webster claims Grew "produced no evidence to support the existence of plant nerves, nor did he mention the idea of plant sensitivity" (18) -- what about his work on plant motion?

experimenters were influenced by human physiology -- Browne, Power, Lister, Clarke (and, we can add, Grew) were all physicians and apothecaries

• "Frances Glisson, one of Europe's most distinguished physiologists, stressed the importance of the study of plant anatomy and utilized information from plant anatomy to support his views on animal physiology." (22)

"the concepts of plant sensitivity and animal irritability materialized simultaneously." (22)

"Evidence about plant movements had been accumulating since antiquity, et the concept of plant sensitivity did not appear until the mid-seventeenth century, during the revival of experimental science, which followed in the wake of the works of Gilbert and Harvey." (23)

"Their [Power, Clarke] simple physiological experiments were not repeated by the members of the Royal Society, whose search for a mechanistic explanation of plant sensitivity neglected the

experimental approach. Conssequently, they failed to establish the idea of plant sensitivity; the impetus of the study of plant movements was largely lost." (23)