. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. 214 DIVISION II.—COURSE OF DEVELOPMENT OF FUNGI. the thallus which is in their way, till at length the space between the excipulum and .the surface of the thallus is filled by an incipient hymenium consisting of paraphyses standing side by side with no gaps between them. The ascogonium has meanwhile at first slowly followed the growth of the excipulum by intercalary growth accompanied by a loosening of the turns of the spiral. As the development proceeds the asco- gen
. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. 214 DIVISION II.—COURSE OF DEVELOPMENT OF FUNGI. the thallus which is in their way, till at length the space between the excipulum and .the surface of the thallus is filled by an incipient hymenium consisting of paraphyses standing side by side with no gaps between them. The ascogonium has meanwhile at first slowly followed the growth of the excipulum by intercalary growth accompanied by a loosening of the turns of the spiral. As the development proceeds the asco- genous hyphae sprout from it, and spread their abundant ramifications through the zone of origin of the paraphyses, the subhymmial layer, in essentially the same manner as in Ascobolus, and thrust the asci as branches of the last order one after another in betw£en the paraphyses (Fig. 102). The species of Physma also examined by Stahl agree with Collema except in the following peculiarities. The archicarps here spring from the hyphae which form the protuberant base of the spermogonia, from four to eight on each spermo- gonium. The ascogonia are but slightly curved and are inclosed in the hyphal. Fig. 102. Coliema tnicropkyitum. Median section through a young apothecium imbedded in the thallus; h and j- as in Fig. 101, b—c excipulum and bypothecium; from the latter proceed crowded upright paraphyses, between which asci are beginning to be formed on the ascogenous hyphae above the hypothecium. After Stahl. Magn. 530 times. weft of the wall of the spermogonium, and the trichogynes protrude beyond the outer side. The discharge of the spermatia of a spermogonium coincides as a rule with the completion of the trichogynes which belong to them, and these become covered with the spermatia adhering to them. Then paraphyses grow out from the wall of the spermogonium into its now empty cavity, displacing the sterigmata, and soon fiU it up in the form of a tuft of filaments which converge
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