PLATE 2. 



0.. Of.wr>wo&/1 



4 «• • 



7 #tif 



• ••I 



6 tpf 



/o 



Hat. size). Alder fruits from different British populations. 3 and 6 are abnormal (galled). 



PLATE 3. 



(x \) Pistillate alder catkins. Left to right : " microcarpa," Woodwalton Fen, Hunts.; 

 " macrocarpa," Chippenham Fen, Cambs.; " microcarpa," N. Arran. 



