406 Journal of Applied Microscopy. 



thirdly, as to whether the ontogenetic development of these wing characters 

 shows a definite series of developmental processes, both as to markings and to 

 the series of colors. Investigations show in reference to the first question that 

 butterfly markings are in general put together from a series of elements that 

 appear successively during the development of the pupa, and are only combined 

 a short time before the butterfly matures. This gradual development of mark- 

 ings shows most clearly in forms of lower phylogenetic standing ; higher developed 

 forms show temporarily the more primitive kinds of marking. The first markings 

 to appear are of generic value. The results of this investigation confirm most 

 thoroughly Elmer's generalizations on the relationship of the Papilionidae. It 

 was found that there is a marked distinction to be made between the ground 

 color and the markings. The longitudinal markings represent the first steps in 

 ontogeny as in phylogeny. First, small longitudinal veins appear, which later 

 fuse laterally, and finally are united by tranverse markings. Among the Van- 

 essas, Vanessa levana shows the most primitive features ; here longitudinal 

 markings are most strongly expressed. The coloring of the wings and the fusion 

 of the veins are first completed on the back and inner parts, and development 

 spreads from these regions forward and outward ; edges and ribs last receive 

 their definite coloring in all cases. In many instances the hind wing developed 

 more rapidly than the fore, and the upper side than the under. The position and 

 course of the veins are dependent on the shape of the wing, hence the imaginal 

 markings of the two wings vary widely from originally similar beginnings. In single 

 cases the position of the veins is dependent on the course of trachea, and it is 

 probable that the origin of the primitive, longitudinal venation of the butterfly 

 could be traced back to a neuropterous arrangement. . It was found that colors 

 appear in the following order : first, light yellow, then orange, carmine, zinnober, 

 and lastly, black. Blue appears after black. a. m. c. 



Van Beneden, Edward. Sur la presence, chez Recent work by Eternod (Anat. Anz. 

 r homme, de un canal archenterique. Anat. .^ i i -i .-• -. o^on i 



Anz. IS: pp. 349-356, 9 fig., 1899. '5: U-13, 1898) on a young human 



embryo suggested to Van Beneden a 

 point of interest observed earlier by himself. It concerns the development of an 

 archenteric canal in man. Its existence has not been observed, but its presence 

 can be safely inferred from the facts presented. Eternod speaks of a solid rod 

 of cells stretching along the whole length of the embryo, excepting in the region 

 of the blastopore, where it is changed into a deep furrow, which the observer 

 suggests may be the notocordal or archenteric canal in its early stages. Van 

 Beneden points out that this embryo, and also another famous one of the Comte 

 Spee, are both more advanced than would be expected for the beginning of this 

 canal, and therefore states that this furrow is the last trace, and not first evidence 

 of this structure. Figures are given of some sections of these young embryos, 

 and some most interesting points brought out. Several new names are given to 

 the different cell masses. The hypoblast is called the " lecithophore," the 

 beginning of the neureuteric canal is named " enteric plate." Originally distinct 

 in origin, these two eventually fuse to a single mass and form an indivisible 

 plate known as the " lecitho-enteric plate." Close study of the sections gives 



