Francis E. Lloyd — 112 — Carnivorous Plants 



tradiction between the results of Tischutkin, who denied the role of 

 other than bacterial digestion, and Colla, who argued the opposite, 

 he states his belief that digestion by the leaf is extraordinarily feeble, 

 and it seemed to Mirimanoff that Pinguicula would better be re- 

 garded as a "semi-carnivore". Following up this hint Olivet and 

 Mirimanoff (1940) re-examined the matter by a new method. They 

 applied {a) a sterilized insect (Drosophila) to a bacteria-sterile leaf, 

 and (b) one to a non-sterile leaf; and (c) a non-sterile insect to a non- 

 sterile leaf. In the first case there was no evidence of digestion, and 

 none of aggregation and no discoloration of the glands. In the second 

 there was an evident discoloration of the glands, and aggregation was 

 observed. Tested, the fly now was swarming with bacteria among 

 which were gelatin-liquifying motile forms. In the last case digestion 

 of the insect proceeded with abundant evidence of aggregation and 

 discoloration. It was tried to obtain the putative protease by diffusion 

 into gelatin-sugar in the cold. On warming at ordinary temperatures 

 there was no liquifaction. They concluded that the digestion of insects 

 on Pinguicula is the result of bacterial activity, and while the authors 

 do not deny the presence of a protease secreted by the plant, they hold 

 its action to be negligible. 



Thus the question has been reopened, and demands further critical 

 examination. 



Pinguicula has long been supposed to have the ability to curdle 

 milk. Linnaeus (Flora Lapponica, p. 10) tells us that the Lapps used 

 it for the curdling of milk and that the peasants of the Italian Alps use it 

 similarly (Pfeffer, through Oppenheimer) . Francis Darwin also 

 records the fact that the same use was made of it by the farmers of 

 Wales "for the past 30 years" as previous to 1875. This probably 

 means a very much longer time (F. Darwin, in a footnote in Darwin, 

 1888). 



The fact that some plants can cause coagulation in milk (notably 

 Galium veruni) was known to the ancients, according to Czapek. It 

 is not clear what precisely the function of a rennet on this plant would 

 be, but it seems that it is not a substance per se, but that the pro- 

 teolytic enzymes have the property of coagulation, as will be seen 

 beyond. In relation to this question, the following quotations were 

 sent me by Dr. Oke Gustafsson, translated and transmitted by 

 Dr. Jens Clausen, to both of whom I owe thanks: — 



"This 'tatort' {Pinguicula vulgaris) has long been used in some of the more northern 

 provinces of Sweden, as for example Jamtland and Dalarne. It has been mixed with fresh 

 milk by smearing either the milk-sieve or the container with the glutinous leaves. For 

 a long time it has been a common view that the milk was changed to ropy- or long-milk 

 by its tough and viscid slime similar to cheese-lep (The milk has been given this name be- 

 cause it is so thick and tough [viscid] that it can be pulled into long strands). Through 

 experiments it has now been found that long-milk cannot always be produced with Pin- 

 guicula (the 'tatort'), if ever, but that on the contrary such milk can originate without 

 this medium." (Lindman). 



Properties and uses in Norway and Denmark. — "When the leaves 

 are laid in milk it will curdle, although without separating from the 

 whey, and this milk, in Norway called 'Ta^ttemaelk' (ropy milk) will 

 make other milk curdle. From this the Norwegian name 'Tsettegrses' 

 (curdlegrass) and the Faroe name 'Undslaeva Greas' have their 



