1888.] NATURAL SCIENCES OF PHILADELPHIA. 73 



FeBRUAPvY 14. 



The President, Dr. Joseph Leidy, in the chair. 



Twenty-two persons present. 



On the resevihlanee of the primitive foravibiifera and of ovarian 

 Ova. — Prof. Ryder remarked that upon cutting sections of nearly 

 mature ovarian ova with their investing membrane, zona radiata, in 

 place, it was found that, in quite a number of cases, fine protoplas- 

 mic processes or pseudopods extended from the peripheral layer of 

 protojilasm of the e.gg, through its capsule or zona and joined the 

 cells of the granulosa or discus proligerus. This arrangement re- 

 minded one forcibly of the filamentous pseudppods extended from a 

 Heliozoon or of the slender pseudopods extended through the per- 

 forations in the walls of the single chambers of Glohigerina. This 

 resemblance was all the more suggestive if one will compare a 

 section of one of the chambers of a Glohigerina made through the 

 calcareous shell and its contained protoplasm with a similar section 

 through the ovum of the Gar Pike, where the zona is formed of 

 pillars of homogenous matter. Such prolongations of pseudopods 

 through the investing zona radiata in the case of many species of ani- 

 mal forms, shows fairly well that this must be the principal means 

 by which new matter is taken up from without and incorporated, as 

 there is no direct extension of the vascular system into the egg, by 

 which it can take up nutriment. It is thus seen that the early 

 stages of the growing ovum, not only resemble some of the lower 

 forms of Helizoa and Foraminifera as respects the grade of their 

 morphological differentiation but also as to the mode in which they 

 exhibit their nutritive or physiological activities. This resemblance 

 is still further heightened if a form like OrhuUna is compared with 

 certain stages of the development of ova. It is thus seen that, in 

 many cases, the ovarian germ, at least, passes through a stage which 

 may be morphologically as well as physiologically compai-ed with 

 some of the lowest 2:rades of the Protozoa. 



b^ 



Chaetopterus from Florida: — Prof Leidy directed attention to 

 specimens which were collected in the trip of Prof Heilprin and Mr. 

 Willcox, at the mouth of the Manatee River. The species appears 

 to be the Chaetopterus pergamentaceus of Cuvier, originally des- 

 ci'ibed from specimens from the AVest Indies. It is a remarkable 

 form. It belongs to the Tubicolae or tube-living worms, but unlike 

 most of these, is devoid of the numerous cephalic appendages, or 

 tentacles and gills. The tube is membranous and laminated in 

 structure and it has the appearance of parchment. The two tubes 

 collected are 16 inches long by fths of an inch in diameter, and 

 tapering towards the ends. An incomplete worm, not well preserved 

 •on account of its delicacy, in its present condition is 9 inches long, 

 6 



