But, as the supreme problem for the biologist is the development of man, so the supreme problem for the astronomer is that of the evolutional order of the stars. This problem, too, is discussed in the light of the discoveries at Tulse Hill. From the simple but beautiful harmonic system of hydrogen lines which characterizes a white star like Vega, we learn how we pass to the more developed star of a solar type, like Capella, and thence to Arcturus, and Belelgueze, which indicate a still later stage of development. At least this is the theory of the author. Aside from its great theme lucidly discussed the book deserves to be upon every library table as a superb specimen of bookmaking. For once, beautiful truth is promulgated in fitting guise. Lady Huggins is an artist and archæologist as well as an astronomer, and the initial letters of the chapters are illuminated with original sketches and designs from quaint old manuscripts, which make the book artistically as well as astronomically worthy of the prize which it received from the Royal Society as the most distinguished contribution to the scientific literature of the year. _EXPERIMENTAL MEDICINE._ Anyone who wishes to gain a fairly adequate idea of what experiments on living animals have accomplished for the welfare of the human race and of other animals as well, can now do so by reading ‘Experiments on Animals,’ by Stephen Paget. Mr. Paget has collected evidence showing the part that animal experiments have played in the progress of physiology, pathology, bacteriology and therapeutics. He has not ventured to offer opinion or even statements unsupported by exact and verifiable facts. A large part of the book’s space is filled by original quotations from scientific workers, from Galen down to the recent students of the malaria parasite. It shows plainly that knowledge of the processes of life in health and disease has throughout depended on experiments on living substances. Mr. Paget’s book is not dependent for its interest solely on the laudable curiosity to know the worth of animal experiments. For these have been so important in the science of medicine that their story is at the same time the history of a great number of medical discoveries. There is, too, a freshness and biographical interest in the quotations from the famous past and present students of medical science which makes them very readable. _ICHTHYOLOGY FOR ANGLERS._