MICROSCOPICAL TECHNIQUE. 87 



objects examined in it into sliarper contrast. In a paper read 

 before the New York Academy of Medicine, he stated that he 

 had worked with a sample having a refractive index of i'593. 

 Bacilli examined in this oil exhibited an unrivalled brilliance and 

 sharpness of contour. The minuter details, also — such as spores, 

 flagella, etc. — are shown with a distinctness impossible in cedar oil. 

 The oil of cassia, like the oil of cloves, tends to abstract the 

 colour from the bacilli stained with some of the aniline dyes, a 

 disadvantage not shared by cedar oil ; but it is stated that this 

 does not take place with sufficient rapidity to interfere with the 

 diagnostic examination. — Pharmaceutical Journal. 



Structure of Yeast"**"— P. Dangeard claims to have proved that 

 the Saccharomyces cerevisice possesses a well-characterised nucleus. 

 His material was fixed with absolute alcohol and stained with 

 haematoxylin, and the details were rendered evident by the aid of 

 a Zeiss' apochromatic objective of 2 mm. focus. The yeast cell 

 under these conditions, is said to show, under the limiting mem- 

 brane, a thick bed of dense homogeneous protoplasm coloured by 

 the reagent. This protoplasm encloses a large vacuole, and the 

 nucleus is found lodged in the thickness of the protoplasmic bed, 

 being described as spherical, limited by a very clear nucleus mem- 

 brane, and containing in the centre a large nucleolus strongly 

 coloured. The mass of hyaloplasm between the nucleolus and the 

 membrane is said to remain free from colour, and one or more 

 threads of chromatin may frequently be seen in immediate contact 

 with the nuclear membrane. When the operation of budding 

 takes place, the bud about to separate and form a new cell makes 

 its appearance at a spot diametrically opposite to that where the 

 nucleus is situated. It is almost spherical, and, like the mother 

 cell, contains a mass of protoplasm enclosing a vacuole. It is 

 attached to the mother-cell by a very fine pedicel, which subse- 

 quently disappears. Up to this stage the nucleus shows no 

 change, but now it moves towards the point of attachment of the 

 pedicel and splits into two parts, each of which consists of half 

 the nucleolus surrounded by a clear hyaloplasmic zone. One of 



* Comptes Rend.f cxvii., 68. 



