254 



STRAWBEREY. 



previously undescribed) he bestowed on it the appellation of 

 Aphelcnchus fragaricB, as descriptive of the nematode and its 

 food-plant. 



Stem Eelwokm {Tylenchus devastatrix). Anterior portion of female showing 

 moutli-spear ; and embryo in egg. All greatly magnified (anterior portion mag. 

 4i0 times). From figures by Dr. J. Eitzema Bos. 



The accompanying much magnified figures of Tylenchus 

 devastatrix may be taken as giving a general idea of the 

 shape of the Aphelenchi, inasmuch as in both cases these are 

 " long eel-shaped .4»/7u//k^ic/^g with a flexible ringed skin"; 

 in both cases also there is a "spear" or "stilet" in the 

 mouth cavity or gullet. The essential differences in structure, 

 which can only be observed with the help of very high micro- 

 scopic powers, I do not enter on here ; but, with the per- 

 mission of Dr. Eitzema Bos, who was good enough to allow 

 me to extract at pleasure from his elaborately minute paper* 

 on this infestation, I offer just a few notes from his measure- 

 ments, &c. ; and likewise his valuable botanical figure (at 

 p. 253), and some notes from his description of the effect of 

 the infestation on the plant growth. 



Dr. Eitzema Bos observes that " this Apkelcnckus fragarite 

 is a small species" (the greatest length of such small amount 

 of males and females as occurred in the plants I sent was 

 found by him to be — of males, 0*85 mm. ; of females, 0"80 mm. 

 — E. A.O.). " The stilet is small; in one specimen I decided it 



* " The Cauliflower Disease of the Strawberry, caused by Aphclcnchusfragaricc, 

 nov. spec," entitled " De Bloemkoolziekte der Aardberen, veroorzaakt door 

 Apltelenclius fragaria, nov. spec," door J. Ritzema Bos (voorloopige medede- 

 Img). Overgedruckt uit het Maanblad voor Natuurwefenschappeu, No. 7, 

 Jaargang 1889. 



