GASTEEOPODES. 303 



of the latter species, given in the Rare and Remarkable Animals of Scot- 

 land, there is an instance of no fewer than sixty-eight of the Eolides being 

 dislodged from a single group. The specimen, first observed on a stalk, 

 afterwards descended among the less accessible parts, from whence it re- 

 appeared in two months, considerably grown, and the parts multiplied, 

 the inseparable concomitant of greater age and dimensions. 



The spawn is produced as an irregular ovoidal albuminous mass, 

 containing 300 or 400 ova. It appears at various seasons, summer or 

 winter, June or December ; but the chief breeding seasons are perhaps 

 March and April. The same specimen spawns repeatedly in masses like 

 a minute sausage, larger or smaller, some measuring three lines in length, 

 some much less. It appeared to me that on one occasion red spawn was 

 deposited by a specimen, fig. 12 ; the same enlarged, fig. 13. 



The ova of all the other spawn were white. Prolific animals are 

 often turgid with spawn, which is visible. When deposited it is com- 

 monly attached to the stalks of the Tubularia, or it is at the surface of 

 the water. Various specimens floating there, spawn in this manner. 



Under favourable circumstances, the ova are seen to be in singular 

 arrangement, as if in long compartments across the mass. Each ovum 

 also is contained in an external ovoidal substance. Thus, the inner or 

 central substance is probably the embryo. 



A portion of spawn being subjected to the microscope, on June 18, 

 numerous objects of those composing it were evidently in motion. This 

 motion, on attentive inspection, certainly originated from the opaque 

 part of the ovum, which, in turning within, presented prominences to 

 the spectator. Many living beings were changing their position without 

 removing, which indicated their confinement by some invisible medium, 

 as they seemed exerting themselves for liberation. A portion of the mass 

 separating soon afterwards, the moving bodies proved to be Nautilines, 

 each within its peculiar ovum or capsule. Fig. 14. Thus, the Nauti- 

 line constitutes the nucleus or white speck. It is the embryo ; and as 

 it advances, the intestinal organs display themselves, as the irregularities 

 of shape which strike the observer's eye. 



On raising and transferring one of the larger masses of spawn, a 



