296 ANNUAL OF SCIENTIFIC DISCOVERT. 



9. The flowers of the narcissus, hyacinth, mignonette, helio- 

 trope, lily of the valley, etc., develop ozone in closed vessels. 

 Flowers destitute of perfume do not develop it, and those which, 

 have but slight perfume develop it only in small quantities. As 

 a corollary from these facts the professor recommended the use 

 of flowers in marshy districts and in places infected with animal 

 emanations, as the powerful oxidizing influence of ozone may 

 destroy them. The inhabitants of such regions should surround 

 their houses with beds of the most odorous flowers. Nature. 



A NEW THEORY OF SLEEP. 



Dr. E. Sommer has contributed to the " Zeitschrift fur Ration- 

 ell e Medicin " for 1869, a paper in which he promulgates the doc- 

 trine that sleep is nothing else than the result of a deoxygenation 

 of the organism. According to this theory, the blood and the 

 tissues possess the property of storing up the oxygen inhaled, and 

 then supplying it in proportion to the requirements of the econ- 

 omy. When this store of oxygen is exhausted, or even becomes 

 too small, it no longer suffices to sustain the vital activity of the 

 organs, the brain, nervous system, muscles, etc., and the body 

 falls into that particular state which we call sleep. During the 

 continuance of this deep repose fresh quantities of oxygen are 

 being stored up in the blood, to act as a supply to the awakened 

 vital powers. Rest produces, though in a less degree, the same 

 effect as sleep in reducing the expenditure of oxygen. 



THE NEW AUSTRALIAN MUD-FISH. 



The general form of Ceratodus forsteri, and its striking resem- 

 blance to Lepidosiren, will at once be seen by the accompanying fig- 

 ure (omitted). The length of the specimen described (which at the 

 time the paper was written was the only individual yet obtained), 

 was about 3 feet; it has a broad flat head, small eyes, and 4 limbs 

 in the shape of flappers. The body is stated to be covered with 

 large cycloid scales, 10 rows on each side. A large gill, opening 

 in front of the pectoral limb, contains well-developed bronchia ; 

 but their accurate examination was not possible, on account of the 

 bad condition of the specimen. A rather large pair of nostrils, 

 situated just below the upper lip, communicates by a short tube 

 with the roof of the mouth. The skeleton of this fish is partly 

 ossified and partly cartilaginous, the vertebrae being pure carti- 

 lage, and the ribs hollow tubes, filled with cartilaginous substance. 

 The palate and upper part of the skull are bony, and the head is 

 covered by 2 large scales. The tongue is very small, and is 

 attached to what appears to be a large hyoid bone, ossified exter- 

 nal!} 7 . The rays which support the dorsal and caudal fin consist of 

 hollow tubes filled by cartilage. In the upper jaw are two large 

 teeth, which Mr. Krefft terms incisors, and which are obviously 

 the representatives of the peculiar teeth in the corresponding 

 position in Lepidosiren. Behind these are dental plates, divided 



