Chapter IX — 113 — Pinguicula 



origin. Especially the milk of reindeer is supposed to curdle. However, 

 it had been impossible for me to obtain information that at the present 

 time this plant is used in Norway for production of ropy milk, be- 

 cause usually the left-overs of milk curdled in this manner are used to 

 thicken fresh milk with. 



"Previously this plant has been accused of producing liver sickness 

 (rot) in sheep but we now know that this is an effect of the liver 

 fluke, Distotnum hepaticum, which lives in wet pastures (Note by 

 J. Clausen, in ep.). The bees seek this plant, but stock do not eat it. 

 It is told that it will stain yellow. It is an indicator of moist, so-called 

 sour soil. In places it is used mixed with linseed oil as a home-remedy 

 against wounds." (Hornemann). 



Dernby considered this whole question fully, citing the popular 

 belief in Scandinavia that both Pinguicula and Drosera procure when 

 in contact with milk a "long", that is, a very viscous coagulum. 

 Although the work of Troili-Petersson and Olsen-Sopp (Centralb. 

 f. Bact. II T^T,: 191 2) shows that these plants have nothing to do with 

 "langmjolk", yet the expressed sap of Pinguicula leaves does have 

 a definite effect on sweet milk, that is, on its casein. It produces a 

 viscous fluid of alkahne reaction, but the casein is not coagulated, but 

 broken down into simpler bodies. Dernby states the foflowing con- 

 clusions from experimental evidence: — (7) Dialysed expressed sap of 

 Pinguicula cannot make milk "thick"; (2) On the other hand it splits 

 casein of milk, but only partly, in a weakly alkaline field, just as 

 it does Witte-peptone under the same conditions; (3) The enzyme is very 

 similar to trypsin, working at an opt. pH of ca. 8; {4) No enzyme of 

 pepsin-erepsin character could be found. 



Therapeutic effects. — P. Geddes pointed out that all alpine peasan- 

 try apply the leaves to the sores of cattle, and its healing effect, if such 

 there is, might be referred to the antiseptic properties. More recently 

 there have been more exact studies made of this property (McLean, 

 191 9) indicating the truth of Geddes' report. 



Summarizing, we may conclude that Pinguicula is a carnivorous 

 plant inasmuch as it catches small insects and digests them, at least 

 in part, by means of its own ferments. The possible part played by bac- 

 teria is not excluded. Its leaves are very sensitive to too great "por- 

 tions" of food as GoEBEL truly said. Only minute insects can be 

 captured in nature, this being a matter of common observation. Large 

 insects or bits of fibrin, unless very small, cause decay beneath with 

 permanent injury to the tissues. A closer understanding of the chem- 

 ical nature of the digestive ferments has been attained by Dernby. 



As to the power of the leaf to move, first observed by Darwin, 

 there can be no doubt of the fact, and that the stimulus, supplied 

 by the application of various kinds of substances, organic and in- 

 organic, is transmitted in some fashion, but only slowly. The short- 

 est time in which Darwin observed movement was 2 hours 17 minutes, 

 the stimulus being transmitted over a very short distance, a matter 

 probably of not more than 2 to 6 mm. Movements can be induced 

 by substances which do not cause increased secretion, such as fine 

 grains of sand, as I have also observed. Increased secretion follows 

 the application of sugar and proteins among others. But that following 



