118 Puget Sound Marine Sta. Pub. Vol. 1, No. 12 



occurrence and fusion of unlike gametes is given for C. tomentosum by 

 Oltmanns (14). He says "Schon Berthold hatte gezeigt, dass nur dann 

 Keimpflanzen von Codium zu erhalten sind. wenn man mannliche und 

 weibliche Exemplare zusammen kultiviert. Ich habe dann im September 

 1896 die Kopulation in der beistehend skizzierten Weise, die einer weiteren 

 Erorterung kaum bedarf, beobachtet." Went (20) suggests partheno- 

 genesis in Codium but Oltmanns says this has not been proved. 



KUster (H) describes a form of asexual reproduction that he found 

 in C. tomentosum. It is simply the rounding up of the contents of a 

 utricle when it has been injured, to form bodies, either colorless or filled 

 with chlorophyll, which are expelled into the water by internal pressure, 

 and grow into new plants. This was not observed by the writer in C. 

 mucronatum. 



The chemical composition of walls, plugs, and mucrons of Codium 

 has not been definitely determined. Previous writers (6, 7, 11) have 

 spoken of the "cellulose" plugs. However, no indication of cellulose in 

 either plugs, mucrons or walls could be obtained with the standard cellu- 

 lose tests, — iodine with sulphuric acid, and ammoniacal cupric oxide. 

 Sometimes ruthenium red, specially in a rather concentrated solution, 

 produced a deep pink color in the plugs and mucrons, which probably in- 

 dicates the presence of a pectin compound. The color did not show in 

 the walls, which may mean that they are of different material, or that 

 they are too thin to show a color readily. 



Dixon (5) found a structure in the utricle of C. tomentosum which he 

 calls an axial strand. He describes it as a central column of a different 

 refractive material in the center of the utricle, which has a club or funnel- 

 shaped head. Structures fitting this description were seen in some pre- 

 served material of C. mucronatum; but owing to the fact tha the ma- 

 terial had been preserved in formalin, it was not certain that they were 

 natural. They were not seen in fresh material. 



The distinguishing feature of this species of the genus Codium is the 

 mucronate tip of the utricle. Various writers have divided this species 

 into three varieties distinguished by the size, shape, and presence or ab- 

 sence of the mucron. Extended observation has shown that such differ- 

 ences alone are not sufficient to split this species into varieties ; and unless 

 there are other differences not mentioned in the descriptions, the division 

 into three forms is not justified, for every type of mucron described may 

 often be found on a single plant of C. mucronaium, the variations depend- 

 ing on the location of the utricle on the plant, differences being explained 

 in part by the age of the utricle and the amount of weathering it has un- 

 dergone. 



Collins (4) gives the following account of Codium mucronatum'. 



