Ixxxiii 



Dr. Engelmann exhibited a living specimen of the Black Spruce 

 (ASt'es nigra > fresh from the Adirondacks of New York, infected 

 with a diminutive parasite of the mistletoe family, which he had 

 named Arceuthobium minutum. All the species of this genus 

 inhabit Conifers. One occurs on Junipers in the Mediterranean 

 and Caucasus regions of the old world. A second was found by 

 Humboldt on Pines on the highest mountains of Mexico ; and 

 several more have been found since on our Rocky Mountains and 

 westward, mostly also on Pines. The peculiarity of this species, 

 discovered about the same time last summer, by two different per- 

 sons in different parts of the State of New York, besides its 

 spring flowering (all the others being autumnal), consists in the 

 occurrence of the sexes in distinct colonies in different trees, male 

 and female plants never, thus far, having been found together on 

 the same trees ; and in the great abundance of individuals on 

 these trees, where the flowering plants almost always occupy the 

 three year old branchlets, while the two year old ones exhibit 

 germinating plantlets like small knots. The necessary inference 

 is that these parasites are propagated, or we should rather say 

 multiplied, by stolon-like fibres, almost analogous to the myce- 

 lium of Fungi, spreading under the bark of the growing branches 

 and always from the older to the younger ones, rather than by 

 seeds, which, though abundant enough, could not produce such a 

 copious and regular crop, and invariably of one or the other sex 

 only. Dr. Engelmann had been elaborating a monograph of 

 this curious genus, which he would offer to the Academy for 

 publication. 



Mr. Lucius H. Cheney was elected an associate member. 



yune 3, 1872. 

 Vice-President Albert Todd in the chair. 

 Fourteen members present. 



Dr. J. B. Johnson made a report concerning the lot of ground 

 which had been offered to the Acadt- my in conjunction with the 

 Historical Society, on condition that the two societies would erect 

 a suitable building thereon. He introduced Capt. Silas Bent 

 and Genl. N. Ranney, from the Committee appointed by the His- 

 torical Society, who were present to confer upon the subject. 



