V\ 1 



PREFACE 



The experience which has led to the writing of this book began in ig2g 

 when, examining a species related to Utricularia gibba, / made an observation 

 of some importance in understanding the mechanism of the trap. This begot 

 a desire to study as many other species of the genus as I could obtain for com- 

 parison, primarily to determine the validity of my conclusions. My feeling 

 that research in this field was promising was strengthened by the discovery that 

 the pertinent literature was singularly barren of the information most needed, 

 that is to say, precise accounts of the structure of the entrance mechanisms of 

 the traps. And an examination of much herbarium material, because of the 

 meagreness of the underground parts of the terrestrial types resulting from 

 indifferent methods of collection, forced the conclusion that, even had other 

 difficulties inherent in studying dried material not intervened, it would be 

 necessary to obtain adequately preserved specimens. This meant a wide corre- 

 spondence and, if possible, extensive travel. The uncertainty of achieving the 

 latter made the former imperative. 



The responses to my requests for help were numerous and generous from 

 all parts of the world, with the result that there came to me from many sources 

 well preserved material which fairly represented the genus, for it brought to me 

 some 100 of the total of 2jo or more species. The most lavish single contribu- 

 tion was put at my disposal by my teacher and friend, Karl von Goebel, 

 who gave me a collection of Utricularia collected by him in the tropics of the Old 

 and New Worlds, and in temperate Australia. Many others, while they may 

 have contributed less in amount, could have been no less generous, for the work 

 of collecting, preserving, packing and posting specimens is by no means an 

 easy job. 



Travels included two journeys, one to Africa and one to Africa and Aus- 

 tralia, the latter made possible by a parting gift from my colleagues of McGill 

 University on my retirement from the Macdonald Chair of Botany in igjj. 

 At the university centres visited I was afforded all kinds of help: laboratory 

 space, guidance to promising localities and means of transportation. Several 

 summers were spent also at the Botanical Institute of the University of Munich 

 on the original invitation of Professor Goebel, seconded, after his death, by 

 Professor F. von Wettstein and his successor Dr. F. C. von Faber. 



During my preoccupation with Utricularia / had to prepare two presi- 

 dential addresses, and I was thus led, as has many another in like circum- 

 stances, to give an account of the whole field of plant carnivory. My interests 

 were widened in this way, and soon I became imbued with the idea of bringing 

 together, and perhaps of adding to, our knowledge of this fascinating group of 

 plants. This extended my list of desiderata. On my requests sent to various 

 correspondents I received material of every group, some living, some preserved, 

 e.g., living material of Heliamphora nutans from the Edinburgh Botanical 

 Garden, where also I saw and studied Cephalotus. 



On the study of the material received from many sources, therefore, the ac- 

 counts in this book rest, and not, in the first instance, on the published papers 



