REVIEWS. 331 



by the rudimentary character of the ovules, every part of which is 

 degraded. There is no albumen or nucellus-tissue to nourish 

 the embryo, and the suspensor does its best to remedy this defi- 

 ciency by elongating and escaping from the micropyle, then fasten- 

 ing itself like a parasite upon the placentas and extracting nourish- 

 ment therefrom. As a result, myriads of seeds never succeed in 

 developing even the pro-embryo. — Sde?ice Gossip. 



Colouring Matter of Pollen. — G. Bertrand and G. Por- 

 rault claim to have established the identity of the colouring matter 

 of yellow or orange pollens of diverse origin with carotin, C26H38, 

 the substance to which the colour of carrots is due. From this 

 generalisation they exclude the dry pollens found in the Urticacece, 

 Graminacece, etc., which owe their yellow colour to the cutinisa- 

 tion of their external membrane. The abundance of fatty matters 

 present prevented the crystallisation of the carotin of the pollen, 

 but its iodide, C26 H38 I2. was prepared. The coloured, crystal- 

 like bodies that appear when pollen rich in oil is mounted in gly- 

 cerine and examined microscopically, are not composed of carotin, 

 but of a fatty body, probably cholesterin, with which the oil is 

 supersaturated. — Conipi. Rend., cxv., 828. 



Offered for Sale, a Private Collection of nearly 1,000 Slides, 

 well-mounted and illustrating most branches of Microscopy ; also a Collection 

 of 236 Sea-weeds. — Apply to C. O. Sonntag, 171 Dalkeith Road, Edinburgh. 



An Introduction to Practical Bacteriology for Physi- 

 cians, Chemists, and Students. By Dr. W. .\Iigula. Translated by M. 

 Campbell and edited by H. J. Campbell, M.D., etc. Crown 8vo, pp. viii. — 

 247. (London: Swan Sonnenschein and Co, 1893.) Price 6s. 



Unless the student wishes to go deeply into the science of Bacteriology, 

 the book before us will doubtless give all the information necessary. It goes 

 minutely into the Examination of Living Bacteria, their structure, form, etc. : 

 Preparation of Media, Cultivations, Staining, Mounting, etc. etc. There are 

 two plates and nine illustrations in the text. 



Modern Microscopv. L, The Microscope and Instructions 

 for its Use, by M. J. Cross; II., Microscopic Objects: How Prepared and 

 Mounted, by ^lartin J- Cole. 8vo, pp. 104. (I^ondon : Bailliere, Tindall, 

 and Cox. 1893.) Price 2s. 6d. 



The joint authors of the volume before us have given to the public a very 

 useful book. The tirst section gives such advice as a novice requires before 

 purchasing a microscope and its accessories, this portion of the book being well 

 illustrated. The second section is by Mr. Martin J. Cole, whose mounted 

 slides, and those of his fathers, Mr. A. C. Cole, are so well known and gener- 

 ally admired. Mr. Cole describes each sejiarate stage of procedure in succes- 

 sive lessons or chapters, which if carefully studied and followed by the student, 



