ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 675 



hours ; water therefore cannot be the medium, as was generally supposed, 

 by which they reach man. It is suggested that the mosquito must be 

 swallowed if the young filariae are to iufect ruan ; but in a postscript 

 Dr. Bancroft notes that they may perhaps gain entrance to the human 

 host while the mosquitos bearing them are in the act of biting. A useful 

 description of the method of keeping mosquitos for studying is given. 



The following is a short account of the life-cycle of F. bancrofti : — 

 The mature parasites in the lymphatic vessels of man are three or four 

 inches in length by 1/90 in. in breadth ; they produce the embryo filariaB, 

 1/90 in. x 1/3500 in., which live in the blood-vessels, swimming about 

 when the host is sleeping and resting when he is awake. Mosquitos, 

 biting a filariated subject during the night, withdraw with the blood 

 some embryo filariae. Soon after they reach the mosquito's stomach 

 they pierce the wall and find their way to the muscles, particularly the 

 thoracic muscles, where they imbed themselves. Nourished by the 

 mosquito's plasma they grow with great rapidity, and by the seventeenth 

 day they have attained their maximum development as far as life in the 

 mosquito is concerned. The fiiaria now awaits the chance of gaining 

 entrance to the human host, there, presumably, to begin another period 

 of development which leads to the sexually mature form of three or 

 four inches. It remains to be proved that this will happen. Besides 

 proving that Culex ciliaris L. is an efficient host, Bancroft has shown 

 that C. notoscriptus Skuse and C. annulirostris are not. 



" Gapes " in Birds.* — Herr Klee gives a concise account of Syngamus 

 trachealis, which is often a cause of considerable loss in domesticated 

 birds. He gives lists of birds known to have been infected, describes the 

 symptoms of attack, gives the life-history of the parasite, and discusses 

 means of preventing the spread of the disease and curative measures. 

 An intratracheal injection of a 5 p.c. watery solution of sodium sali- 

 cylate (Moquet's method) gives the best results. 



Strongylus capillaris in the Goat-t —Herr Schlegel finds that this 

 Nematode is the cause of epidemic broncho-pneumonia among goats. 

 The young are taken in with the food, are returned to the mouth during 

 rumination, and thence find their way to lungs and bronchi. Here they 

 become mature and pair. The embryos reach the mouth, pass through 

 the alimentary canal, and reach the exterior with the faeces. They appear 

 to have a brief free life in damp earth, and then, being taken up with food, 

 begin the cycle anew. Direct infection of one animal by another appears 

 to be impossible. The characters of the parasite, symptoms produced, 

 and means of distinction from other species of Strongylus are described 

 in detail. An interesting point is that the different species are distin- 

 guished by the colour-differences in the worm nodules ; thus S. capillaris 

 forms intensely yellow nodules, S. commutatus dark brown or red-brown. 



New Nematodes.^ — Dr. v. Linstow describes several new or little 

 known Nematodes, and seizes the opportunity to protest against the 

 division of large genera into innumerable new genera. In helminthology 

 this is especially inconvenient ; for in e.g. the genus Taenia the character 



* Deutsch. Tiera/tz. Wochenschr., vii. (1899). See Centralbl. Bakt. u. Par., 

 xxvii. (1900) pp. 466-7. 



t Arch. wiss. prakt. Tliierheilkunde, xxv. See Centralbl. Bakt. u. Par., xxvii. 

 G900) pp. 468-71. J Arch. Mikr. Anat., lvi. (1900) pp. 362-76 (1 pi.). 



