K.— BOTANY 209 



from those obviously showing infection with the attendant faint, sweet 

 smell of green things growing. The art of making cheese goes back to 

 the beginnings of man's pastoral life. It has been held that there is 

 evidence for its preparation in the Swiss lake-villages. Cheese from 

 goats' milk is mentioned in the Iliad, and from the Odyssey it is seen to have 

 played a not inconsiderable part in giving sustenance : the cavern of the 

 Cyclopes had its cheese-dairy. What is said of the preparation shows 

 that there has been little difference since Homeric times. From the 

 fifth century B.c Sicilian cheeses were sold everywhere. J. Ivolas has 

 suggested that the cheeses of Mt. Lesura which Pliny says were brought 

 from Nimes to Rome were Roquefort cheese. 



Moulds of the genus Penicillium play a large part in the ripening of the 

 Camembert-Brie, and the Roquefort-Gorgonzola-Stilton series of cheeses. 

 Milk is first coagulated with rennet or dried calf-stomach linings ; the 

 curd is then separated from the whey, drained and pressed to reduce it 

 to its proper proportions. Subsequent salting modifies the flavour and 

 aids desiccation, but also controls the kind of organism which develops. 

 The various processes are mainly due to enzymes and to bacteria, but the 

 taste of certain cheeses depends largely on the species of Penicillium which 

 develops during ripening. It has always been realised that the district 

 where such cheeses are made has a considerable influence on the finished 

 product ; the local customs of ripening cheeses in special caves used from 

 time immemorial has its reason in the fact that the caves are infected with 

 some particular Penicillium. Thus O. Laxa has recently shown that 

 Nalzory cheese owes its distinctive characters to Penicillium nalgiovensis , 

 which is abundantly present in the caves where the cheese is matured, 

 but has not been found elsewhere in the locality ; he believes that the 

 lungus was introduced in 1885 together with the cheese-manufacturing 

 industry. Last year The Times opened its columns to an eulogy of 

 Stilton. The sale of Quenby Hall was recalled in an article entitled 

 ' The Secret of Stilton '— ' The . . . etc. etc. about the " secret " of 

 Cheesemaking must be taken to include the specific germ of the Stilton 

 cheese. The brushing probably helps to impart that, but the woodwork 

 of the dairy must also play its part. I have heard of a farmer who was so 

 pleased with the results of his cheesemaking that he decided to have the 

 dairy rebuilt on a larger scale, with all sorts of tiling and slate shelves. 

 Thereafter his cheeses lacked their old esteemed special quality, the reason 

 being that the virtue had departed with the germs in the wooden shelves.' 14 



In making such cheeses as Stilton, Roquefort and Gorgonzola, the curd 

 is so managed as to leave cracks between the particles as they are pressed 

 together. These cheeses show marbling of green mould on cut surfaces. 

 C. Thorn and J. N. Currie found that Penicillium roqueforti alone of 

 twenty-one species of Penicillium was able to tolerate the low oxygen- 

 content which they demonstrated in the air spaces. Thorn regards the 

 Penicillium in these cheeses as belonging to the same series though other 

 workers have regarded them as distinct species. In the ripening of the 

 thin cakes of the Camembert type of cheese, the fungus Penicillium 



14 Cf. Enlever trop souvent les poussieres de l'6table et de la laiterie, c'est 

 enlever la creme de sur la lait.- — French proverb. 



