was examined on the 2nd of February, no less than thirty-four Sphærularia occurred, and of these the greater number were fullgrown, though two or three were still quite small.

The youngest, or at least the most immature, specimens which have

b

α

FIG. 1.

FIG. 2.

yet come under my notice are represented in figs. 1 and 2. I found them with two others on the 8th of January last. The male offered no special peculiarity, being as usual about th of an inch in length. The female however, far from being the comparatively gigantic creature which she afterwards becomes, was actually shorter, though thicker, than the male, being only 4th of an inch from one end to the other. She was unfortunately opaque, and being my only specimen in this stage, I was unwilling to dissect her, and can therefore say nothing about her internal structure. The attachment of the sexes was already accomplished, and the female lay as usual, free in the abdominal cavity of the Humble Bee. I was also able to convince myself that the female, though sluggish, had not altogether lost the power of movement. At the end to which the male was attached, it is of course difficult to decide how far the motion is not due to the ⚫ male, but independently of this, a careful watching of the other end, convinced me that there were distinct though slight movements belonging to the female herself.

The male Sphærulariæ are in December, January, and February, more lively, both in appearance and reality, than they are at a later period. I am not, however, able to throw any more light on their internal anatomy. In very small specimens the male was attached quite to the end of the female.

The first thing that strikes us in examining a half-grown female,

FIG. 3.

is that each sphærule is a cell (fig. 3) with a distinct nucleus, and the boundary walls which subsequently disappear, may be easily traced. If the free end of the female be cut off, immediately a considerable part of the contents will be ejected. The structure of the ovary may then be plainly seen (figs. 4 and 5). Its walls consist of elongated lozenge-shaped cells, each with a distinct nucleus and nucleolus. The condition of the ova varies with the size of the female. I have not found any eggs actually laid until the middle of April; nor have I met with any young Sphærularia hatched until a month later. No eggs appear to be produced in the lower portion of the ovary, which we may perhaps call the uterus, but they seem to arise in the upper part of the long single tube which constitutes the female generative organ, and to be pushed gradually forward by the pressure from behind.

The uterus is however not empty, but contained in all the specimens which I examined in the winter and early spring, a very curious rod-like body (fig. 2 and 3a), composed of a great number of minute granules, united together as if by some sticky substance. It lay with its lower end close to the vulva, and in small specimens seemed to distend the uterus, though in larger ones it lay quite free in the cavity.

In specimens examined as late as the end of March, the rod had the same position and nearly the same appearance, but the granules of which it is composed seemed to be rather less closely united together. In specimens about half-grown the rod had an average length ofths of an inch, while in full-grown females it was as much sometimes as 8ths, with a width of about ths. Whether however this was a real increase in size and not merely a development in length at the expense of the breadth, I am not at present able to say.

3

0

In the younger females which I examined the eggs did not descend in the uterus as far as the "rod;" but in more mature specimens, the eggs as they made their way towards the vulva, passed along the side of it without breaking it up, or altering its position.

If therefore the "rod" is in fact a collection of spermatozoa, their access to the eggs is thus simply secured. At the same time, I have not as yet found any similar body in the males, nor do I know at what period, or in what manner, it finds its way into the vagina.

The double series of large cells, which in the female extends from one end of the body to the other, was present in all the specimens examined by me, but the contents of the cells differed much in different stages.

In the summer "each of the large cells contains a thick fluid, and "about seven or eight transparent nuclei, which are of tolerably even "size, and about 10%ths of an inch in diameter." In less mature specimens the nuclei indeed are visible and are attached to the cell walls (fig. 6), but instead of the thick fluid, we find the rest of the cavity occupied by small vesicles, some of them as much as 10th of an inch in diameter, but the greater number from 2000 to 28ths, most of which contain a larger or smaller quantity of acicular (?) crystals. Subsequently these crystals disappear; vesicles which are from 20 to 20th of an inch in diameter, are quite clear and transparent. The nuclei themselves are about 8ths of an inch in

FIG. 6.

diameter and contain a number of small irregular bodies; they are also surrounded by a sort of halo of granules.

EXPLANATION OF THE FIGURES.

1.-Young pair of Sphærularia × 60.
a. male b. female.

2.-Very young pair in outline × 60.

3.- Part of skin of female X 250.

4.-Part of Ovary; a the "rod-like" body.

5.-Part of Ovary × 250.

6. Fat cell x 60; the small vesicles are only represented in one part of the cell.

XLI.-ON THE FORMATION OF THE FLOWER IN THE GYMNOSPERMS. By Dr. Eichler.*

[A RECENTLY published part of Dr. v. Martius' "Flora Brasiliensis" contains the Cycads and Conifers by Dr. Eichler. The number of

Communicated by Dr. T. Thomson, F.R.S.

Brazilian species of these Orders is very small, and there is nothing of a special nature to attract attention. Dr. Eichler has, however, added to the systematic enumeration and description of the Brazilian species, a treatise on the morphology and affinities of these two Orders, in an essay which he calls "Excursus morphologicus de "formatione florum Gymnospermarum." This essay is complete in itself, not only as a resumé of all that has been done in this most important branch of Morphology, and as a careful abstract of the general structure and modifications of the two families, but also as giving new views of their structure, lucidly, if somewhat lengthily explained, and supported by ingenious arguments. So important, indeed, do we consider it, that we believe we shall be conferring a favour on our readers by giving them a tolerably copious abstract of the contents of this valuable paper without for the present expressing any opinion of our own on the correctness of the theory which it advocates.

After a few preliminary paragraphs, in which the importance of the study of the morphology of Gymnosperms is pointed out, our author proceeds to his immediate subject, beginning with]

I. THE MALE FLOWER.

We may easily satisfy ourselves that each antheriferous scale of the male amentum of Conifers is a single leaf altered by metamorphosis, that is to say, a single stamen. This is proved in many ways. These leaves not unfrequently assume forms passing into true leaves or into bracteoles. This I have myself observed in Podocarpcae and Cupressineae, and it has been recorded by Schlacht in monstrous aments of Araucaria. In androgynous aments of Abietinae, we find stamens in place of the outer scales, which are true bractiform leaves. Further, the history of the evolution proves that the antheriferous scale springs from its earliest youth quite simple and free from the axis exactly like a true leaf, and is in no way, as is sometimes believed, formed by the union of several parts. This I consider to be beyond a doubt.

Now as all foliaceous organs contributing to the fructification, so long as they are collected in a simple axis, are properly referred to one and the same flower, it follows, from the absence of other floral leaves on the axis of the ament, that a simple male ament forms a single male flower. This flower is in some cases, as in Podocarpus, Taxus, &c., preceded by prophylla or bracteoles.