26 An Abnormal Shoot of Pinus Thunbergii Pari. 
Strasburger 1 described and figured a case of fusion by their 
adaxial margins of the needles of Pinus Pumilio Haenke ; Mr. L. A. 
Boodle informs me that he has seen similar fusion of needles in 
P. sylvestris L. and P. muricnta D. Don; the present writer has 
seen the specimens which he collected. In these cases the fusion, 
however, was sometimes by the adaxial and sometimes by the 
abaxial margins. 
These cases of Pinus are not wholly comparable with those of 
the recurved fleshy leaves of P. Thunbergii Pari, and with the 
“double needle” of Scindopilys; for the needles of Pinus are not 
the first-formed leaves of the axillary shoot, being preceded by a 
number of scale-leaves; they may be also variously orientated, a fact 
which will account for the variation in the mode of marginal fusion. 
The best comparison of all may be made between our recurved 
leaf and the ovuliferous scale of the Abietineae, for, according to the 
most popular view of the latter, the mode of origin of the two is 
precisely identical. In both cases, also, one or two leaves situated 
at a higher level on the axillary shoot have become incorporated 
into the double foliar organ; the apophysis or umbo on the adaxial 
side of the ovuliferous scale finds its replica in the curious outgrowth 
(representing the tip of one of the next pair of leaves) occurring in 
the upper part of the adaxial surface of the fleshy recurved leaf. 
With regard to the physiological meaning and cause of the 
abnormal condition of the piece of shoot, the equilibrium of the 
whole has evidently become upset, possibly by the presence of a 
fungus, which has been ascertained to be present. 2 The axillary 
shoots have been stimulated to an exceptional degree and mode of 
development, but the reason for the particular forms which they 
have taken is obscure. 
At any rate, the phenomenon of the recurved leaf and its mode 
of origin lends strong support to the prevailing view of the morpho¬ 
logical nature both of the ovuliferous scale of Abietineae and of the 
“needle” of Sciadopitys. For it indicates the existence of a 
tendency in the Coniferas for the first two leaves of an axillary 
shoot to unite by their adaxial margins to form a single dominant 
axillary foliar organ. 
The abnormal shoot under discussion affords, further, a 
powerful substantiation of the view that teratological phenomena 
are often of great value in throwing light on the nature and origin 
of otherwise obscure structures. 
1 Strasburger, “ Die Coniferen und Gnetaceen,’’ 1872, p. 387. 
2 Mr. G. Massee investigated the shoot for this purpose. 
