Botanical Society of Edinburgh. 237 



thus produced is always more or less of a syrupy nature, and when 

 evaporated to dryness, a large quantity of saccharine matter is left. 

 Various conjectures have been hazarded as to the origin of the so- 

 called vinegar-plant, some stating that it came from South America 

 or other distant regions, and others that it is a spontaneous produc- 

 tion. Lindley states that it is a peculiar form of Penicilliurn glaucum, 

 or common blue mould. There seems to be no doubt that it is an 

 anomalous state of mould or of some fungus, and the peculiarity of 

 form and consistence appears to be owiog to the material in which it 

 grows. In place of producing the usual cellular sporiferous stalks, 

 the mvcelium increases to an extraordinary extent ; its cellular threads 

 interlacing together in a remarkable manner and producing one ex- 

 panded cellular mass, with occasionally rounded bodies like spores in 

 its substance. The cellular filaments may be seen under the micro- 

 scope. The tendency to divide in a merismatic manner is common 

 in many of the lower classes of plants, and this seems to be what 

 occurs at a certain period of growth, when the plant divides into two 

 horizontal plates. If the plant is allowed to continue growing, it 

 forms numerous plates one above the other. The anomalous forms 

 of fungi in certain circumstances have lately excited much interest, and 

 Mr. Berkeley has called attention to some of the remarkable trans- 

 formations which they undergo. These are such, that many forms 

 considered as separate genera are now looked upon as mere varieties 

 of one species. 



That mould of various kinds when placed in syrup shows the same 

 tendency to form a flat gelatinous or somewhat leathery expansion is 

 shown by the following experiments. 



Some mould that had grown on an apple was put into syrup on 

 the 5th of March, 1851, and in the course of two months, there was 

 a cellular flat expanded mass formed, while the syrup was converted 

 into vinegar. Some of the original mould was seen on the surface in 

 its usual form. 



Some mould from a pear was treated in a similar way with the same 

 result ; also various moulds growing on bread, tea, and other vege- 

 table substances ; the effect in most cases being to cause a fermen- 

 tation, which resulted in the production of vinegar. 



In another experiment on the 8th of November, 1850, a quantity 

 of raw sugar, treacle, and water were put into a jar without any plant 

 being introduced, and they were left untouched till March 5, 1851. 

 When examined, a growth like that of the vinegar plant was visible 

 and vinegar was formed. The plant was removed and put into fresh 

 svrup, and again the production of vinegar took place. 



It would appear from experiment, that when purified, white sugar 

 alone is used to form syrup, the plant when placed in it does not 

 produce vinegar so readily, the length of time required for the changes 

 varying from four to six months. There may possibly be something 

 in "the raw sugar and treacle which tends to promote the acetous 

 change. 



Dr. Greville remarked that he had no doubt that the vinegar-plant 

 was an abnormal state of some fungus. It was well known that 



