692 SCIENCE PROGRESS 



last the other cells form the dear old blood-cells with which we have been so 

 friendly from our youth. Every one of them has a name, not, alas, Tom, Dick, or 

 Harry, but those found in the glossary at page 337. 



As in so many of these books, there is no line of demarcation between fact and 

 fancy. Assertions are made right and left. Certain cells come from the bone- 

 marrow— so it is alleged ; and others come from the spleen. True, in some of the 

 assertions evidence pro and con is discussed ; but as a rule many of the old theories 

 are stated as point-blank facts — especially if they have emanated from Pappenheim 

 or Heidenhain, who were arch-speculators. All this sounds very fine and builds 

 up a pretty book, especially in the introduction describing the blood-cell factories ; 

 but when we come to analyse it we are forced to the conclusion that most of it is 

 the outcome of deduction based on observation through the microscope of dead 

 structures artificially stained. The number of experiments described is very small, 

 most of the book is merely morbid and physiological anatomy — or rather histology 

 — and speculations based on them. Peripheral blood-cells are killed by some force 

 such as heat, or some reagent, and are then stained in their flattened and contracted 

 state. Bone-marrow or spleen or other tissue is treated in a similar way after having 

 been shredded with a razor. Because the cells or parts of them in one class of slide 

 resemble those in the other, it is deduced that the one class of cell developed into 

 the other. No one has followed the development in the living tissues ; but, never 

 mind, it is all swallowed, especially if it agrees with the ideas of Pappenheim. The 

 red-cells come from the normoblasts in the bone-marrow ; but has any one ever seen 

 a living cell come from the bone-marrow and undergo transformation? Hyaline 

 lymphocytes are talked about without granules, and leucocytes are said to divide 

 by multiple mitoses within their so-called nuclei. But has the author made these 

 cells divide in the living state by means of the auxetics to which he l-efers ? The 

 biology of the blood-cell means the birth, reproduction, and death of the living cell, 

 yet tn-vitro staining is mentioned in the same breath with deductions from fixed 

 films ; is there then no difference between life and death ? The blood-platelets 

 are still described as extruded nuclei of red-cells or as precipitates, in spite of 

 published proof to the contrary; Kurloft's bodies in the guinea-pig are still described 

 as evidence of degeneration when it has been proved that they are parasites. 

 Degeneration is a term still glibly used although there is no definition as to what 

 it means to the living cell. 



Dr. Gruner's enthusiasm is so encouraging and his powers of research are so 

 great that we may expect better things of him. Let him shroud his Pappenheim 

 and other authorities, and take to common-sense experiments in a laboratory. 

 When he has worked out his subject according to his own thoughts and originality, 

 giving due regard to the differences between life and death and between theory and 

 fact, it is to be hoped that he will write another book in his charming style. 



The book is elegantly bound and printed, the plates and photomicrographs are 

 beautifully reproduced ; the zoological names are not printed in italics, nor are the 

 generic names spelt with a capital initial. 



