OF AHTS AND SCIKNCES. 185 



in this stajre ; its leuszth is 13 cm. The rhizo<fen is 5 mm. from the 

 primitive cli.sk, wliich is slightly larger than in the last specimen 

 described, but not otherwise different. The rhizogen itself is about 

 4 mm. in diameter. It has several lobes of some length, which are 

 already started downward. The blade presents no particular differ- 

 ences in form, but in specimens of this stage it is very rare indeed to 

 find any trace of the primitive blade remaining. 



In somewhat older specimens the finger-like projections have reached 

 the substratum, have flattened their tips against it, and have become 

 attached to it. There are usually five projections, and they form a 

 whorl of attaching organs, which constitute the second holdfast. They 

 are called bapteres by most recent writers,* after the term used by 

 AYarming f to designate very similar organs in the Poduslemacece. 

 The hapteres form a regular whorl (cf. Figs. 7 and 9), and their 

 points of attachment form a circle about the point of attachment of 

 the primitive disk (cf. Fig. 8). The development of the hapteres 

 marks the end of the first stage of what is to be the permanent 

 holdfast of the plant, and confirms De la Pylaie's statement quoted 

 above. 



3. Development of the Second Hapteres. — In the next series of 

 forms, the second and last stage of the permanent holdfast is formed 

 in a manner essentially the same as that in which the first stage was 

 developed. On the rhizogen above the primary whorl a new whorl of 

 protuberances appears. These protuberances are in most cases regu- 

 larly alternate with the hapteres of the first whorl, but may at times 

 be so placed that one or more of this set are situated above similarly 

 placed hapteres of the first whorl. While the new hapteres are 

 developing, the older hapteres increase in length, and on this account 

 come to occupy a more upright position (cf. Fig. 7 with Fig. 9). 

 The new hapteres, therefore, have the opportunity of growing down 

 obliquely, and of attaching themselves to the substratum, after the 

 manner of those of the first set. Their points of attachment form a 

 second but rather irregidar circle outside the one made by the ends 

 of the primary hapteres. We now have three sets of attaching 

 organs : first, the primitive disk ; second, the primary whorl of hap- 

 teres, all of which are usually present at this stage ; and third, the 

 secondary whorl of hapteres. It often happens that some of the hap- 

 teres of the second set remain as mere protuberances after the rest of 



* Foslie, Die Lam. Norwegens, pp. 6 and 7, 1884. Barber, Antials of Botany, 

 Vol. 111. p. 48. 



t Bot. Zeit., Bd. XLI. pp. 193 and 197, 1883. 



