210 



INTRODUCTION TO CRYPTOGAMIC BOTANY. 



1. ECTOCARPEyE, xig. 



Filiform, articulated ; spores or cysts external, sometimes 

 formed by the swelling of a branchlet. 



194. "We begin with the simplest forms, in which the frond 

 is composed of a single simple or branched thread, or coated 

 with cells, or very rarely solid and cellular below, giving off 

 sub-globose spores or cysts filled with a dense endochrome, and 

 active granules contained in distinct organs. There is some 

 doubt about the nature of the former, whether they are simple 

 or compound organs, unless indeed Ectocarpus spluericus, 

 D. and S., in which the globose lateral cysts were observed to 

 give rise to active bodies, be considered decisive of the point. 

 As regards the podlike organs, Thuret has shown, beyond all 

 question, that their office is to produce zoospores, and analogy 

 would lead us, even apart from E. sphcevicus, to suppose that 

 the endochrome of the other bodies is resolvable into zoo- 

 spores of another order, as in Ulvacece. Be this as it may, the 

 two organs are for the most part seated on distinct individuals, 

 and it is probable that all the siliculose Edocarpi are mere 



Ficr. 53. 



a. Ectocarpus sphcerosporus, Carm. From a specimen commimicated 

 by Mr. Ealfs. 



h. E. pusillus. From specimens gathered by Mrs. Griffiths. Both 

 kinds of fruit appear on one of the threads. 



c. E.fenestrutus^ B. From specimens sent by Mi-s. Griffiths. 



d. E. fasciculatus and silicule. From specimens sent by Mr. Ealfs. 

 All more or less magnified. 



