354 THE NATURALIST, 



Sparrow Hawk (Falco nisus). — In Kovenil3er last, one of these daring 

 little fellows w^as captured at Alnmouth, in a very singular manner. It 

 pursued a sparrow into a joiner's sIiojd, in whicli two workmen Avere engaged, 

 wdio immediately giving cliase, cauglit tlie bold intruder before lie could make 

 good liis escape. It proved to be an immature male, possessing that rich 

 russet brown tint, which I think excels in beauty the plumage of his elder 

 brother the mature bird. The total length of this bird is fourteen inches, 

 wings nine inches, wdiicli is perhaps rather above the average size. 



AlmuicJc, March, 1865. 



THE OEIGIIs^ OF H^MATOZOA IN^ THE HUMAN AIS^D A:N"IMAL 



SYSTEMS. 



Uy Edwin Eoxton-Eirby, F.A.S.L., &c. 



Very recently I was much interested in an examination of those curioils 

 parasitic animalcules frequently found in the blood of mammiferous animals, • 

 of birds, fishes, reptiles, and even in many of the invertebrata ; hence their 

 distinctive name Haematozoa, from Greek Jiaima, blood, and zoon, a living 

 being. They have not, I believe, been found to possess reproductive organs, 

 and whether they propagate by spontaneous fission, or by vesicular encysta- 

 tion, or by the elimination of gemmules from the parent body, similar to the 

 mode of gemmiparous reproduction observed in the fresh-water polyp or 

 hydra, I cannot indeed decide; but I may observe that they are generally of 

 such infinitessimal minuteness, as to be difiicult of inspection without micros- 

 copic aid. Some privileged few are said to attain to a pretty large size, and 

 to be in possession of organs of reproduction, but these individuals are 

 restricted to some special part of the body. The variety called Dlstoma 

 hmmatohiurii is only to be discovered in the abdominal venous s^^stem ; while 

 another variety of tliese minute animal organisms is solely confined to the 

 equine abdominal arterial system — the said system of the horse appearing to 

 be its sole habitat. That known under the name of Pseudcdhis filum is 

 restricted to the pulmonary artery and its ramifications in the porpoise. There 

 is much unccrtaint}^ amongst naturalists attaching to the origin of these 

 entozoa, but it would seem highly probable that they are conveyed into the 

 blood by the larvse being sw^allowed in turbid water. It has been even 

 said that they are the larvce of a worm living in the organs immediately 



