ACADEMY OF NATURAL SCIENCES. 317 



portions : the upper portion consisting of pure ether apparently, then a layer 

 containing white flocculi, which occupied about the fourth part of the fluid, and 

 below this the remains of the original fluid, but little altered in appearance. 

 There can, I think, be little doubt but that it is through the medium of this 

 fluid that the fcetus obtains its nourishment. The considerable portion of ani- 

 mal matter it contains, and that too in a state particularly fitted for absorption 

 and for conversion into tissue, fits it for furnishing the fcetus with the elements 

 necessary for its growth by absorption through the large surface of capillary 

 vessels which are found in the vascular digitations that surround the fcetus, and 

 which are constantly bathed in the fluid. The difficulty that up to the present 

 time has attended every attempt to trace the connection between the parent 

 and fcetus in these embiotocoid fishes, is owing, in the first place, to the ex- 

 treme delicacy of the vascular digitations of the fcetus, which prevents their 

 being observed in preserved specimens, and also to the fact that in almost 

 every case the fluid secreted by the uterus is entirely expelled by the violent 

 struggles of the fish when removed from the water, so that it was almost by 

 a rare accident that I succeeded in obtaining any. I hope, however, during the 

 coming season, to be able more fully to carry out these researches. 

 San Francisco, January 21st, 1867. 



Mr. Bolander exhibited the cones of many species of pines grow- 

 ing in this State, and stated what was known concerning the 

 peculiarities of the different species, and their geographical distri- 

 bution. 



He stated that the pines of California comprise sixteen true species, which 

 he described briefly. There are twenty synonyms for these species, which have 

 created some confusion as to their real name and number. The correct names 

 of all, with the popular characteristics of the most striking, and their distribu- 

 tion, are given herewith. The names marked thus * are those of trees having 

 persistent cones, which they retain from ten to twenty years in some instances. 

 Those marked thus f retain their cones but two years. Those marked thus J re- 

 tain them but one year : 



Pinus insignis.* — Well known as the ornamental Monterey pine, which is 

 much cultivated in San Francisco. 



P. muricala.* — Not remarkable. 



P. contorta.* — Small and bushy, but valuable as shelter against wind. Grows 

 abundantly near Fort Bragg, in the Mendocino < country, where it makes the 

 stoutest wind-proof hedge known. Ought to be tried in San Francisco. 



P. tuberculata* — Always small, seldom higher than 15 to 30 feet. 



P. ponderosa.X — The well known yellow pine. Attains a height of 225 feet 

 and more, and a circumference of 23 or 24 feet. 



P. Lambertiana.* — The equally well known, larger and handsome "sugar 

 pine," or "long-cone piue" of Fremont. Usually grows at great altitudes ; 

 exceedingly valuable for timber, and affords the principal supplies. 



