TRANSACTIONS OF THE SECTIONS. 133 



which they were subjected to ebullition under a pressure of 2 inches or more of 

 mercury. The result was negative. There was no development of Bacteria. 



Since the publication of these experiments Huizinga s have appeared. His 

 result, regarded as a proof of spontaneous generation, is clearly not superior to 

 Bastian's. His substitution of a soluble immediate principle for an insoluble mixed 

 product like cheese, and the use of a definite solution of sugar and salts, are not 

 material improvements. The question is not whether the germinal matter of 

 Bacteria is present, but whether it is destroyed by the process of heating. Conse- 

 quently what is necessary is not to alter the liquid, but to make the conditions 

 of the experiment, as regards temperature, as exact as possible. In this respect 

 Iluizinga's experiment is a confirmation of Bastian's, and nothing more. 



I have recently repeated Huizinga's experiments with the same modifications as 

 regards temperature as tliose employed in my repetition of the turnip-cheese experi- 

 ments. The result has been the same. In all essential respects I have followed 

 the method described by him in his paper. I have prepared the solution of salts, 

 grape-sugar, and peptone in exact accordance with his directions. To obviate his 

 objection as to the absence of air, I have introduced the liquid, not into flasks, but 

 into strong glass tubes closed hermetically at each end and only half filled with 

 liquid, the remainder of the tube containing air at the ordinary tension. Each of 

 these tubes, after having been subjected to the temperature of ebullition under 2 

 inches of mercury for half an hour, has been kept since September 10 at the tem- 

 perature of fermentation (32° C). Up to the time of my leaving London for 

 Bradford no change whatever had taken place in the liquid. 



As a control experiment I opened one of the tubes immediately after boiling, and 

 introduced a drop of distilled water. It became opalescent in twenty- four hours. 



On the Electrical Plienomemt, wliich accompany the Contractions of the Leaf of 

 Dionaea muscipula. Bi/ Dr. Btjrdon Sanderson. 



It is well known that in those structures in the higher animals which are 

 endowed with the property of contracting when stimulated, viz. nerve and muscle, 

 this property is associated'with the existence of voltaic currents which have defi- 

 nite directions in the tissue. These currents have been the subject of very carefid 

 observation by physiologists. They require delicate instruments for their investi- 

 gation, but the phenomena dependent on them admit of the application of the most 

 exact measurements. The constant current which can be shown to exist in a 

 muscle is called the normal current. The most important fact with reference to it 

 is that it exists ouly so long as the muscle is alive, and that it ceases during the 

 moment that the muscle is thrown into action. Other characteristics of the 

 muscle-currents were referred to, which we have not space to mention. 



In certain plants said to possess the property of irritabilit}-, contractions of cer- 

 tain organs on irritation occur which strikingly suggest a correspondence of func- 

 tion between them and the motor organs of animals. Among the most remarkable 

 are those of Drosera and some other plants belonging to the same natural order, 

 particularly the well-known "\"enus's Flytrap (Dionati viuscipulu). The sensitive 

 plant, the common monkey flower, the rock CiHus, afford other examples. 



Strange as it maj' seem, the question whether these contractile movements are 

 accompanied with the same electrical changes as those which occur in the con- 

 traction of muscle and in the functional excitation of nerve has never yet been 

 investigated by vegetable physiologists. Mr. Darwin, who for many years has 

 devoted much attention to the animal-like functions of Dioncea and Drosera, 

 kindly furnished plants for the purpose of the necessary experiments, which have 

 been made by Dr. Sanderson in the laboratory of University College, London. The 

 result has been that the anticipations he had formed have been confirmed as to the 

 existence of voltaic currents in these parts, and particularly in the leaf oi Dionaa. 

 By a most remarkable series of experiments, made with the aid of Sir W. Thomson's 

 galvanometer, he has shown that these currents are subject, in all respects in which 

 they have been as yet investigated, to the same laws as those of muscle and nerve. 



