ZOOLOGY 



REGISTRY OF PERIODICAL PHENOMENA. 



THE following observations on the registry of periodical phenomena 

 have been issued in a circular by the Smithsonian Institution : 



The Smithsonian Institution, being desirous of obtaining information 

 with regard to the periodical phenomena of animal and vegetable life 

 in North America, respectfully invite all persons, w r ho may have it in 

 their power, to record their observations, and to transmit them to the 

 Institution. The points to which particular attention should be di- 

 rected, are, the first appearance of leaves and of flowers in plants ; the 

 dates of appearance and disappearance of migratory of hybernating 

 animals, as Mammalia, Birds, Keptiles, Fishes, Insects, &c. ; the times 

 of nesting of birds, of moulting and littering of mammalia, of utterance 

 of characteristic cries among reptiles and insects, and anything else 

 which may be deemed noteworthy. The Smithsonian Institution is 

 also desirous of obtaining detailed lists of all the animals and plants of 

 any locality throughout this continent. These, when practicable, 

 should consist of the scientific names, as well as those in common use ; 

 but when the former are unknown, the latter may alone be employed. 

 It is in contemplation to use the information thus gathered, in the con- 

 struction of a series of tables, showing the geographical distribution of 

 the animal and vegetable kingdoms in North America. 



ON THE INFUSORIA OF DUST SHOWERS AND BLOOD RAINS. 



THE infusorial character of the dust occasionally transported by 

 winds is one of the most wonderful of Ehrenberg's discoveries. His 

 investigations have been reported from time to time since 1844, but a 

 recent publication contains the details of all his researches, with full 

 illustrations. The plates contain not only the figures of all the forms 

 observed in each case, but a sketch of a portion of the dust as it lay 

 under the microscope, exhibiting to the eye the relative prevalence of 

 different forms, and the colors they presented. Ehrenberg favors the 

 view of the atmospheric origin of these showers, and speaks of their 

 relation to the fall of meteorites. Chaldini, in his work on meteorites, 

 observes that the stones which fell between 1790 and 1819 amounted 

 to not less than 600 weight ; while for the single dust-shower of 

 Lyons, in 1846, the material that fell was full 7200 weight. The Cape 



