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body, iu which is a matrix that develops many fat globules ; the anus is situated 

 at the beginning of the hyaline portion of the tail end. The larva now leaves 

 the cyst cavity and enters a fresh root or a different place in the same root. 

 It wanders for a time, when it comes to rest, molts a second time and then being 

 fixed enlarges, or " swells up " into a cyst with a flask-like body, the head pro- 

 jecting at one end and the slender pointed tail at the other. At this time promi- 

 nent sexual transformations take place. Hale: The male molts again (th?rd 

 time) leaving the outer Avall of the cyst intact, while the body of the male elon- 

 gates, narrows, and becomes coiled three or four times within the cyst. While 

 this change is going on the male molts again (fourth time). It is now from 1""" 

 to 1.5""" long, anguillula-like, blunt at each end. slightly curved at the caudal 

 end where are two curved spicules. In the middle line of the body runs the 

 alimentary canal, in the posterior half of the l)ody are the paired testes, which 

 are united into a common duct near the caudal end and at the cloaca this unites 

 with the intestine. On each side within the body is a muscular cord extending 

 the entire length of the worm. Female: The female does not molt again, but 

 continues to enlarge enormously until it is gourd-shaped, and the paired gen- 

 erative organs, opening by a common passage at the vulva in the posterior part 

 of the body, form long tubes which lie coiled in the body of the cyst, free at their 

 anterior end. As the embryos are developing the body of the cyst breaks up 

 into an amorphic, gelatinous mass in which the young larvie and eggs are found 

 floating within the cyst cavity. Length of life cycle, one month. 



Attention is called to the very close resemblance between H. radi- 

 cicola and //. schachtiL The author seems to be doubtful whether 

 they are really distinct species, and desires to make further studies 

 before deciding whether his own observations include more than one 

 species. He also remarks on the wide distribution of the genus 

 Heterodera in various parts of the world, and is inclined to believe 

 that the nenuttodes may grow much further north than has been sup- 

 posed. 



I'he external form of the gall is to a great extent dependent upon the number 

 of worms and their distribution in the tissues of the roots, as well as upon some 

 specific peculiarities in the growth of the roots or habit of branching. If the 

 worms are numerous and the attack is made pretry regularly in a peripheral 

 plane at a particular point in the root, the gall will be symmetrical, and either 

 short and ovoid or elongate and fusiform, according to the extent of their distri- 

 bution along the axis of the root at that point. If fewer worms attack at a given 

 point the gall is more likely to be lateral, owing to the less certainty of an even 

 peripheral infection. Often, however, lateral galls may be so near as to unite 

 into one, when the appearance is that of a very irregular and knotty gall, the en- 

 largements passing by aijrupt changes on different sides of the root. 



The similarities and differences of root-galls, potato scab, and 

 " club-foot '' of cabbage are pointed out, and the root-galls are also 

 distinguished from the " tubercles " found on the roots of leguminous 

 plants, which seem to have such an important connection with the 

 acquisition of nitrogen from the air by these plants. 



Rotation of crops and clean cultivation arc suggested as^ among the. 

 means for eradicating the nematodes or checking their spread, but the 

 author wisely thinks that further investigations are needed before 

 positive remedies can be recommended. 



