The President's Address. By Wm. Carruthers. 121 



that the seeds of one genus should produce another ; for instance, that 

 the seeds of Ly coper da should produce Mucores. However, 1 have 

 determined to go through these experiments with precision, and to 

 call in witnesses of the several appearances. 



" I have not yet got any of the Vstilago. If you will be so good 

 as to send me a spike of corn infected with it, proper for trial, you 

 may depend on me in carefully going through the experiments 

 properly." 



Linnasus soon replied to this letter, though, as wo see, under a 

 misapprehension : — 



" I am beyond measure delighted with your observations upon the 

 Lycoperdon in river water; that its powder moved about, and was 

 transformed into that species of Mucor which I have named Mucedo. 

 I have long suspected this Mucedo to belong to Lycoperdon ; but my 

 suspicion has never before been confirmed." 



Ellis wrote again very soon, January 1768 : — 



" In your letter of the 8th December, you seem to misapprehend 

 the meaning of the letter which I wrote to you the 30th October. I 

 find, on looking over the copy which I have of it, it runs thus, or 

 much to this purpose " — and he repeats the statements he had already 

 made. He then continues, " Thus far I thought it necessary to 

 quote from my former letter of 30th October, as my real opinion. I 

 have kept a regular journal of my observations in making experiments 

 on the seeds of the Fungi, which I have shown often to Dr. Solander, 

 to prevent any mistake ; and do assure you I have convinced him that 

 they do not move of themselves when kept in water ; but it appeared 

 evidently to him, and many more gentlemen who saw my experiments, 

 that the motion which they had proceeded from animalia infusoria, 

 whose shape we plainly saw, and observed distinctly the particular 

 motion, with some attention, which these little creatures had while 

 they were eating the seeds of the Fungi, and which they communi- 

 cated to the seeds of the Fungi, so as to make them appear alive." 



He records the results of further experiments on animalcules in a 

 letter written in the following March : — 



" I have now discovered why putrid vegetable substances yield 

 volatile alkaline salts, the same as animal substances. I put a rotten 

 potato into water about ten days ago, in a glass, and covered the top 

 with a card, having a weight on it to keep it close, and placed it on a 

 shelf in a room over the fire-place. In four days the water was full 

 of small animalcules, so that, I believe, for every particle of the 

 potato there were ten minute animals, as in the experiments with the 

 Fungi. In order to know for certain whether these animals came 

 from the potato or the water, I boiled a small potato till it was 

 ready to fall to pieces. I likewise boiled some water for half an hour, 

 and then put the mashed potato and the boiled water together in a 

 glass, and they were placed in the same warm situation with a card 

 over it. I examined a drop of the liquor four days after, and could 



