E. S. Salmon and H. Wormald 243 



stems (" bines ") are pulled off from the rootstock, and the remaining 

 2 — 3 stems' are " trained " up the " strings " (of coir yarn), for the first 

 4J feet vertically to a lower wire, then at an angle of approximately 45° 

 to a top wire 11 ft. 6 in. from the ground supported on poles-. The soil 

 was uniformly and fairly heavily manured and good cultivation was 

 given to the whole hop-garden. 



The hop plant, Humidus Lupulus L. is a dioecious perennial with a 

 persistent underground rootstock from which develop long annual climb- 

 ing shoots. The main axis of a shoot (or " bine ") bears decussate leaves 

 from the axils of which develop the primary bi'anches (" laterals "). The 

 lower laterals are usually barren but the rest form much-branched 

 paniculate inflorescences. The rootstock of the seedling plant during its 

 first year is very small and the shoots comparatively weak and the plant 

 does not attain to full vigour for several years. Observations regarding 

 morphological characters were therefore not taken until the plants were 

 in their third year and even then some characters, particularly those 

 depending upon vigour, e.g. length of the laterals, could not be regarded 

 as constant. 



As the plants approached an age when the various organs assumed 

 the characters shown by the mature plant it was seen that there were 

 marked differences in certain morphological and physiological characters. 

 That some at least of these differences were not mere fluctuations due 

 to environmental conditions was shown by keeping the plants under 

 observation for several successive years and noting which characters 

 remained constant (or fluctuated within comparatively narrow limits) 

 for the individual plants. 



The plants were first critically examined in 1916 and the characters 

 noted of those plants which were old enough for the purposed Many of 

 the plants have thus been under observation during five seasons, the 

 rest during from two to four seasons. 



The variations which have been observed are concerned with the 

 following points : 



1 In a few cases the seedlings were planted 6 feet 6 inches apart in the row, and 6 stems 

 trained up the strings. 



- The system of wire work used in the Hop-garden is that known as the "Butcher." It 

 has been described by A. Amos in the Journ. Board Agric. YoL xvi. p. 890 (1910), where a 

 detailed account is given of the English method of cultivating hops. 



3 The variation shown by a number of male hop plants growing in the Experimental 

 Hop-garden at Wye College and known, or believed, to be derived from seeds of cultivated 

 hops, has already been recorded (2). The methods of observation and description adopted 

 in that instance have been applied (modified and extended where necessary) in describing 

 the plants noted in the present paper. 



