Tin: MAKixi: alg.e of new exglaxd. 15 



and sprin;^- than at other seasons, if we excei)t a lew ^a'nera, like Ecto- 

 curpns. The eonjuj^ation in this suborder was lirst seen by Aresehoiifi: 

 in I>icti/osij}lion, and afterwards by Cloebel in Ecfocarpus pusillns. The 

 zoospores unite in nearly the same way as in the Chlorosporca'. Aecord- 

 injx to Goebel, who studied the zoospores coming from idurilocuhir 

 sporani^ia, the eonjn.uation oceurs Ix'tween zoospores eoniinLr from dif- 

 ferent sp(»ran;jfia. Tiie di'velopment of the zygos[)ore and the action of 

 the zoospores borne in the unilocular sporan«;ia, except in the ^renus 

 Dicfifosiphon^ are not yet satisfactorily known. Thun^t and r)Ornet have 

 seen bodies which they consider to be antheriiba in several species of 

 EctocarpuSj and Pringsheim at one time considered that he had found 

 antheridia in a species of S2)h(tcclaria. It is now admitted that the bodies 

 found by Prin<2:sheim belonj^ed to a parasitic si)ecies of Chytridium, and 

 Thuret and Bornet were unable to ascertain the development of the 

 antheridia in Ecfocarpus. At any rate, nothing- like an oogonium or any 

 female or;;an to be fertilized by the antherozoids has been found in the 

 riiwosporecv. 



As has already been hinted, the <^enera of Phfvosporccv differ from 

 one another very widely in the structure of the frond. From low 

 forms, consisting of short lilaments, we pass upwards, through various 

 cylindrical, crustaceous, and globose forms, to the highly developed 

 devil's aprons, Laminarca'j the largest of our sea-weeds; and, finally, 

 on the coast of California and in the Antarctic Ocean, we find the per- 

 fection of the order in the enormous Macrocystis pyrifcra^ which is sev- 

 eral hundred feet long; the Sereocyfitis or bladder-kelp of California ; and 

 EgrcgUtj in which we have what appears to be a separate stem, leaves, 

 bladders, and fruit-bearing leaves. Janczewski distinguishes three i^rin- 

 cipal modes of growth of the thallus in PJuvosporccv. The first consist 

 in growth from a single terminal cell, as in Sjyhacclaria^ Cladostejohus^ 

 and D'wtyosiphon^ resulting in the formation of a filamentous solid i)lant. 

 The second mode consists in the simultaneous growth of several contigu- 

 ous filaments at their tips, so as to form either a flat expansion, as in 

 Myrioncma and Ralfsia, or a more or less globular body, as in Leathcsia. 

 The third mode is illustrated by the genus Laminaria, in which there is 

 a stalk, a blade, and root-like growths. The i)lace of gnnvth is at the 

 point of union of stem and blade, and the new blade, which begins to 

 form at the tip of the stem, grows upwards fi'om the base and gradually 

 pushes off the old blade. In Scyfo.siphon a similar mode of growth is 

 found only here, there being no stalk, the growth is at the base of the 

 plant. During a certain jiait of the year, especially in the spring, most 

 of the I*hfcofiporr(t are covered with delicate hairs, which disai)pear as 

 the plant becomes old. 



The suborder contains a large number of species, which arc divided 

 into several families. Those fi)und on our coast are the Ibllowing: 



ScYTOSiPiiONE.'E.--This family includes the two genera Scytosiphon 

 and PhylUtuij which comprise the old Chorda lomcntaria and Laminaria 



