CESALPINO ii 



of his dated Nov. 26, 1565 (Epistolae Medicae, 1577, p. 113) 

 that he too was seeking for the basis of a natural system of 

 classification and that he thought he had found it in the flower 

 and the fruit: "Ex his enim notis (a fructu, semine and fare) 

 potius quam foliis, stirpium naturae et cognationes apparent'' 



Evidently at this period classification was in the air, and at 

 length it began to precipitate and to crystallise in the work of 

 Andrea Cesalpino (Caesalpinus : 1519 1603), Professor in the 

 University of Pisa, whose De Plantis Libri XVI, published in 

 1583, is one of the most important landmarks in the history of 

 systematic Botany. Here for the first time a system is pro- 

 pounded which is based definitely upon morphological observation. 

 Cesalpino turns to the " fructification," that is the flower and the 

 fruit, for his distinguishing characters. " Enitamur igitur" he 

 says (Lib. Leap, xiv.), "ex propriis quae fructificationis gratia data 

 sunt, plantarum genera investigare " ; and he goes on to point 

 out that the observable differences here depend on number, 

 position and form of the parts : " ad organorum constitutionem 

 tria maxime faciant, scilicet, partium numerus, situs et figura" 

 These principles he illustrates as follows : the flower being the 

 outermost covering of the fruit, a single flower may cover a single 

 seed, as in the Almond : or a single seed-receptacle as in the 

 Rose : or two seeds, as in the Umbelliferae : or two seed-recep- 

 tacles, as in the Cress: or three seeds, as in the genus TitJiymalus 

 (Euphorbia} ; or three receptacles, as in the Bulbaceous plants 

 (petaloid Monocotyledons) : or four seeds, as in Marrubium : or 

 four receptacles, as in Etwnymus : or many seeds, as in the 

 Cichoriaceae : or many receptacles, as in the Coniferae. The 

 feature of the relative position of the parts which he especially 

 emphasizes is whether the flower is inserted upon the top of the 

 fruit (i.e. is epigynous) : or is inserted lower around the fruit 

 (hypogynous or perigynous). Moreover, the form of the seed, of 

 the seed-receptacle, and of the flower, is to be taken into account. 



The practical application of these principles led to a classifi- 

 cation of plants which, though of course imperfect, was at least 

 a good beginning. Following Theophrastus, Cesalpino divided 

 plants into two main groups, (i) Trees and Shrubs, (2) Under- 

 shrubs and Herbs : each of these groups was then subdivided 



