i894. RESEARCHES ON SEAWEEDS. 53 



The reproduction oi Adenocystis is by zoospores, borne in zoosporangia 

 and the cryptostomata occur in the middle of sori of unilocular 

 sporangia." The paraphyses and sporangia, which are truly 

 Laminarian, grow on the very edge of the depression. " In the 

 other Laminarieae examined, the sorus occurs separately from the 

 cryptostomata, but, in this form, in the middle of the sporangia 

 and paraphyses, as if in a nascent effort (or a dying one, as the case 

 may be), to form a conceptacle like that of Splaciinidinm. It will 

 be remembered that a young conceptacle of SplacJmidium bears hairs 

 only at first and sporangia later on." 



In Hydvoclathnis, cryptostomata are described by Miss Mitchell 

 as occurring among plurilocular sporangia. 



Mr. Murray concludes his paper by alluding to Professor Bower's 

 remark about the groups of hairs in the Dictyotaceae, " which are the 

 precursors of the reproductive cells." Professor Bower says : " How 

 far these may be compared with the initial cell or hair of the 

 Fucaceae, it remains for closer observation to decide." Mr. Murray 

 attaches a prophetic value to this utterance, and notes that 

 Falkenberg has pointed out " that in Scytosiphon single epidermal 

 cells within a sorus remain sterile and grow out in the form of 

 club-shaped unicellular paraphyses." Hairs are also found in 

 Aspevococcus and other allied forms, arising in similar situations, 

 " resembling the hairs in the conceptacles and cryptostomata of 

 the Fucaceae, Splachnidmm, Saccovhiza, and Adenocystis, and those in the 

 sorus of Cutleriaceae and Dictyotaceae." 



In conclusion, I cannot do better than quote here the summing- 

 up of Mr. Murray's interesting paper. " A comparison of the 

 Fucaceous conceptacle and cryptostoma, the Splachnidian conceptacle, 

 with its persistent initial cell and the formation of its hairs yielding 

 place to sporangia, the development of the Adenocystis cryptostoma 

 in the heart of its sorus, the other Laminarian cryptostomata 

 (Saccorhiza and Alafia) apart from the sorus, the cryptostoma of 

 Hydroclathrns among its plurilocular sporangia, and finally the cases 

 of the hairs in Aspevococcus and the Cutleriaceae and Dictyotaceae — a 

 comparison of these cases and of the evidence plainly furnished 

 by them points very significantly to a possible origin of crypto- 

 stomata." These are striking admissions by one who has heaped 

 contempt on " the ancestors of the Fucaceae." 



Such is the present state of our knowledge of the history and 

 development of cryptostomata. Links are still needed to complete 

 the chain of evidence which is to connect the hairs growing out from 

 the surface of the Dictyotaceae with the well-developed conceptacles 

 of the higher forms of the Fucaceae. But there are types still to be 

 examined, and much interesting work to be done. The foreign forms 

 of the Laminarieae may, and probably will, show variations and 

 gradations in the scale of development hitherto unsuspected, and we 

 may look forward to most interesting results when any worker 



