∗ Cultivation of the Virus of the Common Cold in the Chlorio-Allantoic Membrane of the Chick Embryo

We have reported the successful cultivation of the virus of the common cold in an anaerobic medium containing chick-embryo tissue. 1 , 2 Our purpose in the present communication is to describe the cultivation of this virus in the chorio-allantoic membrane of the developing chick-embryo.

This technic for the cultivation of the viruses of infectious diseases was developed by Woodruff and Goodpasture 3 for the propagation of fowl pox virus, and later successfully applied by them and others to a number of different viruses. Wilson Smith 4 reported the cultivation of a mouse-passage strain of human influenza virus by this means. A more elaborate series of similar experiments has already been recorded by Burnet. 5

Our own experiment was as follows: In September, 1936, a nasal washing was obtained from an individual with a typical acute head cold of less than 24 hours' duration. The washing was passed rapidly through a Seitz filter, and concentrated to one-fourth its original volume by vacuum distillation. Two-tenths cc. of this bacteria-free filtrate, almost immediately after its isolation from the human source, were inoculated into the chorio-allantoic membranes of 12-day chick-embryos according to the technic described by previous authors. At the end of 2 or 3 days the membranes were removed and ground up with non-toxic broth so as to make a suspension of approximately 20%; 0.2 cc. of this were inoculated into each of a second series of eggs. Similarly these membranes were ground up and inoculated into a third. It is noteworthy that the small opaque foci visible on the membranes and which Burnet 5 described as resulting from the cultivation of influenza virus were also observed by us.