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ANATOMY, AND LIFfi-HISTORY OF THE CONIFERiE. 



325 































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The winged seeds also seem to afford ample provision for dispersal. 

 In some cases (Abies) the seeds are liberated by the loosening 

 and falling away of the fruit- scales ; in other cases (Picea) the 

 fruit-scales simply separate for a short space, whilst in some 

 species of Pinus the cones remaiu attached to the branches with 



their thick woody scales firmly closed for an unlimited period, 



only opening, as it would appear, when the forest-fires cause 



them to split asunder and liberate the seeds. It is noted that 



the trees in these forests are all of about the same age and 



dimensions, a fact accounted for by the circumstances just 

 mentioned. 



That the scales of the young cone should separate ore from 

 another at the tips to permit of the ingress of pollen is readily 

 intelligible; but the corresponding movements to facilitate the 

 egress of the seeds are not so well known. I have no experience 

 of my own to offer on this subject, but the following extract 

 from a communication of Mr. Albert Prentiss on the Hygro- 

 scopic Movements in the Cone-scales of Abietinese may be read 

 with interest : 



" In most of the Abietineae, soon after the maturation of the 

 cones, the persistent scales fall backward or outward from the 

 axis to permit the ripened seed to escape. The scales are very 

 sensitive to moisture, and in many species exhibit very rapid 

 movements when wet, as with rain. This is especially well seen 

 in the cones of Tsuga canadensis, in which the widely open scales 

 become completely closed in twelve minutes. This property of 

 the cone-scale is found to be very efficient, first in loosening the 

 winged seeds from the scale which bears them, and secondly in 

 favouring the wide dispersion of the seed as the cones open and 

 close many times before all the seeds are sown, thus securing 

 their transport in different directions by the varying winds " *. 

 In Museums it is a common practice to restore the original form 

 of a cone in which the scales have separated one from the other 

 from drought by soaking it in water. 









* Prentiss, in ' Botanical Gazette' (1888), pp. 236, 237 



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