18(X ^Fr TTenry Goodsir on a New Genu^^ 



duct. They act in the following way : — The ova, as they in-* 

 crease in size, cause a considerable degree of pressure on the 

 membranous septa, and especially on the septum, separating 

 the last ovum fom the empty part of the cell ; this by its- 

 resistance throws tlie pressure on the circumference of the 

 cell, this being the weakest part, and the ovum at the same 

 time extending longitudinally, the smaller end of the egg is 

 thrust through the coats of the duct, and thus becomes free. 

 In each of the cells just mentioned, there is an eggy so that 

 the oviduct consists of one row of eggs only. 



Thus, as the ova increase in size, the membranes of the 

 oviducts become tense, and burst, and the ovum escapes, but 

 still remains attached to the oviduct, by means of the ovisac, 

 which acts as a cord ; the ovum remaining attached to the 

 oviduct by this means, until the young animal is ready to 

 bluest from the egg. After the young animal has escaped 

 from the ovum, it remains for a considerable time attached 

 to, or near, the parent animal. The ova belonging to the 

 distal half of the oviduct are generally freed from their at- 

 tachment to the mother altogether, before those in the proxi- 

 mal half are ready for exclusion from the oviduct. They 

 burst, with very few exceptions, from the external edge of 

 the oviduct ; and 1 have never seen them burst through the 

 membranous septa. They are of a flat shape while in the 

 oviduct, bearing considerable resemblance to a double con- 

 vex lens ; after they have escaped from the oviduct, they 

 become more spherical, and when placed under a powerful 

 glass, the young animal is distinctly seen through the trans- 

 parent membranes. The young animal at this stage is of a 

 brown colour, with various streaks of purple ; the body is of 

 a conical shape, and a constriction or neck separates it from 

 the head. There is no appearance of antennae, but there are 

 one pair of feet on each side of the body, which divide at 

 their extremities into several long slender spines. 



When examined during this stage, under a powerful glass, 

 by means of transmitted light, nothing is perceptible but cel- 

 lular structure in different degrees of density. The intestinal 

 canal is also perceptible. When the ovum is a little more 

 a<lvanced, there is sometimes, altliough not always, the ap- 



