1. column of liquid blood confined within an elastic tube. There have been many detailed studies of the anatomy of the perivascular space (Weed, 1914; Woollam and Millen, 1954). None indicates any way in which its structure could have this effect. In a situation of this kind where a narrow liquid cylinder is held within an elastic boundary it is likely to take an unduloid form, even if it does not completely break up into droplets. According to Plateau (1867) the theoretical limit of stability is reached when the length of a liquid cylinder is at least equal to its circumference. However, with increasing viscosity this instability is less, and the unduloid shape may not be apparent until a greater length of liquid is formed, nor will the individual droplets be so spherical. Such a difference in form was indeed noted between the type II structures consisting of blood and those which were produced artificially by the more viscotus gelatine injection medium
2. Echoencephalography in the differential diagnosis of cerebral haemorrhage and infarction;Achar, V.S.; Coe, R.P.K.; Marshall, J.;Lancet,1966
3. Vascular diseases of the brain;Adams, R.D.; Vander Eecken, H.M.;Ann. Rev. Med,1953
4. In Greenfield's Neuropathology by Blackwood;Blackwood, W.,1963
5. Nouvelles recherches sur la pathog6nie de lh6morrhagie c6r6brale;Charcot, J. -M.; Bouchard, C;Arch. Physiol. Norm. Path,1868