24 First Report on Economic Zoology. 
Fig. 3. — scale, false scale and effect of frost and canker. 
a, Mussel scale on apple wood ; s, the scales ; ol, mussel scale enlarged ; «2, its eggs ; b, pear 
twig showing grey scale-like spots (normal plant structure) ; c, apple twig blistered 
by frost and canker (?), not insect work ; u and c, blistered area. 
