300 GEORGE W. BARTELMEZ 



the chalazal axis when the egg is oriented in the funnel. A word 

 should be said here with reference to the chalazae. Normally 

 they are attached to either end of the long axis, but sometimes 

 this attachment is irregular. Patterson ('09, p. 68) found this to 

 be the case in 8 per cent of the eggs ; however he included in this 

 category, cases in which only a button is attached to the in- 

 fundibular end of the egg, and no chalazal thickening appears. 

 There are other cases in which the chalazae are not attached to 

 the ends of the long axis, i.e., in which the long and chalazal axes 

 do not coincide. I observed six such out of 299 eggs, namely 

 2.2 per cent. Considering the mechanical factors involved in 

 the orientation in the oviduct, this much abnormality is to be 

 expected. Accordingly, the results described here on the relation 

 of embryonic to long axis may be compared with those on its 

 relation to the chalazal axis which are given by the previous work- 

 ers who overlooked the long axis. 



Blount ('09) and Patterson ('09) are the only authors who have 

 made statements with regard to the relation between the embry- 

 onic and long axes in the pigeon. The latter author states that 

 the angle between them is 45 degrees in 90 per cent of the cases. 

 No estimate of the probable error was given in the method of 

 measurement that was used, which was to orient the egg under the 

 binocular so that the chalazal axis was parallel to the base line 

 of a square ruled micrometer scale in one ocular, then to note the 

 position of the embryo, and derive the angle. There are several 

 sources of error in such a method and the observations were fur- 

 ther hampered by the fact that many of the measurements were 

 made on primitive streak stages. (It should be noted that the 

 angles given by Patterson are the complements of those given 

 here.) The method used in this study was to remove the shell 

 in salt solution, noting the relations of the smaller end of the shell, 

 the heavier chalaza, and the air chamber, for the two former mark 

 the end of the egg which went down the oviduct first and are 

 invariably opposite the air chamber. After it had been noted 

 that the long and chalazal axes coincided, the base of a protractor 

 was laid parallel to them, and without moving the head, a slip of 

 glass 3 mm. wide was moved over the protractor so as to coincide 



