The south polar snow-cap is seen at the top, and as it is early June on this part of Mars, the snow-cap has become small. The dark line across it is a wide rift, the ice having commenced to break up at this part; and the dark shading round it is water from the melting snow. The circular light area near the centre is "Hellas," and the dark wedge-shaped area is "Syrtis Major." The protuberance usually seen on the eastern side of Syrtis Major has this year almost disappeared, and but little detail is visible anywhere.] For instance, M. Antoniadi, of Juvisy Observatory, near Paris, has published a very interesting account of his own observations with the fine Meudon refractor, which has an object glass 32.7 inches in diameter; and he has also furnished several beautifully executed drawings of what he has seen. The most noticeable new features observed were two large detached pieces of the south polar snow-cap, the altered shape of the Solis Lacus and other dark areas, numerous dark rounded spots on the dark areas, much detail along the lines of the canals, and the observation of scattered markings instead of lines. M. Antoniadi lays great stress on the advantages of large telescopes; and, whilst making frank admission that the drawings of Professor Lowell show the outlines of the Martian details more accurately than the drawings of any other observer, he dissents entirely from his views respecting the actuality of the canal lines. With regard to M. Antoniadi's observation of dark rounded spots, it has been suggested by another writer that these are volcanoes, and, moreover, that the canal lines are really cracks in the solid ice covering frozen oceans and seas. These contentions involve the supposition that Mars is still in the stage when volcanic action is prevalent, and also that what have hitherto been supposed to be desert lands are really fields of ice. Mars has passed far beyond the stage of volcanic activity; and the theory does not account for the ochre colour of the frozen oceans, which are exactly the same colour as our deserts appear when viewed from a great distance, for the sandstorms so frequently observed, nor for the general absence of any indications of frost over a large portion of the Martian surface. It is also very difficult to imagine the existence of a profuse growth of vegetation along cracks in solid ice; and I am afraid this theory, like many others, fails to fit in with the observed facts. I may remind my readers that the Professor suggested that many more dark rounded spots would, under favourable conditions, be discovered on the dark areas of the planet, and he has stated what they are.