He showed that the archicarp consisted of two parts, a lower coiled portion, the ascogonium, and an upper portion, the trichogyne, which projected from the thallus.
Only when a spermatium was found attached to the trichogyne did the further development of the ascogonium take place.
This view was hotly contested by many workers and it was sought to explain the trichogyne - without much success - as a respiratory organ, or as a boring organ which made a way for the developing apothecium.
A, Carpogonium, c, with its trichogyne t (X405).
B, Apex of the trichogyne with the spermatium, s, (X405) attached (>0125).
The female organ is essentially a flask-shaped structure; the neck of the flask growing out as the trichogyne, and the belly composed of an axial carpogenic cell surrounded by investing cells, and with one cell (trichophoric) between it and the trichogyne.
These three elements - trichogyne, trichophoric cell, and carpogenic cell - are regarded as the procarp. The spermatia have been shown by Thaxter to fuse with the trichogyne, after which the axial cell below (carpogenic cell) undergoes divisions, and ultimately forms asci containing ascospores, while cells investing this form a perithecium, the whole structure reminding us essentially of the fructification of a Pyrenomycete.
In Coleochaete the oogonial wall is drawn out into a considerable tube, which is provided with an apical pore, and this tube has a somewhat similar appearance to the imperforate trichogyne of Florideae to be hereafter described.
This is the carpogonium; it consists of a ventral portion which contains a nucleus, but in which no oosphere is differentiated, and an elongated tubular portion known as the trichogyne, into which the cytoplasm extends.
Fertilization is effected by the passive convection of a spermatium from the antheridium to the trichogyne, to which it adheres, and to which it passes over its nucleus through an open communication set up at the point of contact.
The nucleus then passes down the trichogyne and fuses with that of the egg.
The ventral portion of the carpogonium may be imbedded deep in the thallus in the massive species; the trichogyne, however, always reaches the surface.
The first effect of fertilization is the occlusion of the trichogyne from the fertilized carpogonium.
Batrachospermum sp., trichogyne with spermatia attached; carpo B.
The male cell is a spermatium, but the female cell bears no such receptive trichogyne as occurs in other Rhodophyceae.
Fertilization by means of non-motile spermatia and a trichogyne are known among the Fungi in the families Collemaceae and Laboulbeniaceae.